Here's a rundown of as many of the questions/problem/issues that have been noted by myself and others:
Wick
The length varies from barely spanning the tube to being a healthy length. Very short wicks are easily dislodged and tend to burn drier.
The wick is often almost centered and thus visible from the battery hole. Some report the wick is pushed off-center and not visible from the battery hole. It's suggested that an off-center wick performs better. Perhaps better wicking? If the fiberglass is impregnated, contact may not be a good thing.
Coil
The coils may be tightly compressed, or have a slight gap. The coil can be wound tightly or loosely. It's suggested a tight coil performs better, perhaps because it runs cooler being in better contact with the juice. When loosely wound, the leads may cross back over the coil. If arcing occurs, the wires will superheat.
The coil position varies from centered on the wick, pushed against the side of the wick/tube, straddling the slit, or outside the slit.
The coil is typically close or flush with the battery end of the shell which puts it in close proximity (1/16"-1/32") to, if not directly touching, the silicone adhesive and/or the silicone sleeve.
Wire leads
Vary from being recessed into the battery hole to having an extremely very small bend on the end from extending above the hole. The variance may bring the coil into contact with the silicone sleeve.
Depending on positioning of the wires, they appear to short against the shell under load and drop the resistance. The wires vary from being 180 degrees opposite, to 90 degrees which might increase the possibility of shorting. If arcing occurs, the wires will superheat.
Battery tip
Applying light pressure similar to snugging on a battery may change the resistance on some cartos. When it happens, the resistance may drop to ~1ohm. May be due to improperly positioned wires that bow under pressure and short against each other and/or the shell.
Silicone sleeve
Scorches are often seen on the lower end of the sleeve. I've seen it divot the tip of the sleeve. The wire leads have been observed to melt depressions in the sleeve w/o scorching it. Melted/scorched silicone releases toxics/carcinogens.
Arcing or shorting of the wires will superheat and damage the silicone.
Silicone adhesive
Wildly varies from thick fat ring, to paper thin ring, to barely enough to adhere to the sleeve. The adhesive is not pure silicone so it contains additives that will outgas during heating and/or melting. We need to know what the additives are. Additives tend to be very nasty stuff.
Arcing or shorting of the wires may damage the adhesive.
I've repeatedly eliminated foul nasty taste by removal of the adhesive. I'm getting tired of kindly being told it's not an issue with no supporting evidence.
Fiberglass sleeve
Appears to be impregnated with something. After subjecting to heat, the texture changes and it loses its springiness. Rolling it will release dust, which is either ash from an additive, fiberglass shards, or both. We need to know what it may be impregnated with.
Overall
The variances indicate that QC is poor. It's going to be hard to achieve consistency with this design and manual assembly by an army of cheap labor.
The current wick and wire length appear to be barely sufficient which is leading to excessive failure rates. I know it's all about increased material cost and decreased profit. Given amazing similar cartos with the same packaging foil, soft cap, etc cost <$.55 each in bulk, I think a few pennies can please please please be spent to make these safer?
My very simple suggestions would at a minimum be:
1) Replace the silicone adhesive with pure silicone and consistently use a tiny amount. Although the need for adhesive could easily be removed with no additional materials...
2) Increase the length of the wick to comfortably extend outside the tube.
3) Eliminate any possibility of the coil contacting the silicones by increasing the length of the wire leads to distance the coil from the silicone sleeve and adhesive by ~1/4".
4) Use the increased wick length and inner wrap to firmly hold the wick in place to prevent it from dislodging or the coil from contacting the tube.
Wick
The length varies from barely spanning the tube to being a healthy length. Very short wicks are easily dislodged and tend to burn drier.
The wick is often almost centered and thus visible from the battery hole. Some report the wick is pushed off-center and not visible from the battery hole. It's suggested that an off-center wick performs better. Perhaps better wicking? If the fiberglass is impregnated, contact may not be a good thing.
Coil
The coils may be tightly compressed, or have a slight gap. The coil can be wound tightly or loosely. It's suggested a tight coil performs better, perhaps because it runs cooler being in better contact with the juice. When loosely wound, the leads may cross back over the coil. If arcing occurs, the wires will superheat.
The coil position varies from centered on the wick, pushed against the side of the wick/tube, straddling the slit, or outside the slit.
The coil is typically close or flush with the battery end of the shell which puts it in close proximity (1/16"-1/32") to, if not directly touching, the silicone adhesive and/or the silicone sleeve.
Wire leads
Vary from being recessed into the battery hole to having an extremely very small bend on the end from extending above the hole. The variance may bring the coil into contact with the silicone sleeve.
Depending on positioning of the wires, they appear to short against the shell under load and drop the resistance. The wires vary from being 180 degrees opposite, to 90 degrees which might increase the possibility of shorting. If arcing occurs, the wires will superheat.
Battery tip
Applying light pressure similar to snugging on a battery may change the resistance on some cartos. When it happens, the resistance may drop to ~1ohm. May be due to improperly positioned wires that bow under pressure and short against each other and/or the shell.
Silicone sleeve
Scorches are often seen on the lower end of the sleeve. I've seen it divot the tip of the sleeve. The wire leads have been observed to melt depressions in the sleeve w/o scorching it. Melted/scorched silicone releases toxics/carcinogens.
Arcing or shorting of the wires will superheat and damage the silicone.
Silicone adhesive
Wildly varies from thick fat ring, to paper thin ring, to barely enough to adhere to the sleeve. The adhesive is not pure silicone so it contains additives that will outgas during heating and/or melting. We need to know what the additives are. Additives tend to be very nasty stuff.
Arcing or shorting of the wires may damage the adhesive.
I've repeatedly eliminated foul nasty taste by removal of the adhesive. I'm getting tired of kindly being told it's not an issue with no supporting evidence.
Fiberglass sleeve
Appears to be impregnated with something. After subjecting to heat, the texture changes and it loses its springiness. Rolling it will release dust, which is either ash from an additive, fiberglass shards, or both. We need to know what it may be impregnated with.
Overall
The variances indicate that QC is poor. It's going to be hard to achieve consistency with this design and manual assembly by an army of cheap labor.
The current wick and wire length appear to be barely sufficient which is leading to excessive failure rates. I know it's all about increased material cost and decreased profit. Given amazing similar cartos with the same packaging foil, soft cap, etc cost <$.55 each in bulk, I think a few pennies can please please please be spent to make these safer?
My very simple suggestions would at a minimum be:
1) Replace the silicone adhesive with pure silicone and consistently use a tiny amount. Although the need for adhesive could easily be removed with no additional materials...
2) Increase the length of the wick to comfortably extend outside the tube.
3) Eliminate any possibility of the coil contacting the silicones by increasing the length of the wire leads to distance the coil from the silicone sleeve and adhesive by ~1/4".
4) Use the increased wick length and inner wrap to firmly hold the wick in place to prevent it from dislodging or the coil from contacting the tube.
sorry cryx i couldnt resist but yes You have put in A LOT of research into this and to be honest before you first posted I would 
