Note: I just realized how old this post is so I'm sure you've already got everything resolved.
I started with Smoketip and although I now purchase from many other vendors, I've never had a problem with Smoketip. I think their customer service and responsiveness are pretty good.
To fill them just pop off the cap and remove the plastic ring, then drip new stuff onto the wicking material.
I prefer this method versus the condom method, which IMHO wastes a lot of e-liquid. Be careful no matter which method you use. Smoketip batteries are automatic and can be easily destroyed if e-liquid drips into it. So
never refill a carto when attached to the battery, and be certain to blow excess out of the carto before using it, even if you think it's not been overfilled. Do a search on something like "refilling a carto" - there's numerous threads on the subject. There's also numerous threads on how to clean them, although many people don't bother with it if they're refilling with the same or similar flavor.
The wire in there is the atomizer. Its actually a little coil of heater wire
The Smoketip cartomizers have what's called a horizontal coil, which sits at the very bottom (battery end). So you won't see a wire. BTW, horizontal coil cartos work better, IMHO, so you might not like those with vertical wires. I know the bloog maxfusion cartos are horizontal, but they're pricey. I know there's a lot of others with horizontal coils, but I'm not sure who they are, but I know there are numerous threads on the subject (I know there's a pretty good one in the KR808D model specific forum).
Smoketip only supplies what are known as shorty batteries.
They also sell a longer 102mm battery. It has a capacity of 350MaH, so it lasts much longer than the 'shorty'.
How may time can these things be reused
There's no definitive answer to this. As someone else said, once the filler get's burnt, the carto is toast. Eventually enough 'gunk' builds up and performance goes down and it's time to toss it. I've refilled some 20-30 times while others don't last nearly as long.
I notice some of the brand new cartomizers from Smoketip have a wicked burn as soon as I take a puff
I've gotten some bad cartomizers from Smoketip too. There seems to variability in them, with some producing tons of vapor and lasting a long time, while others don't produce well and don't last long. I believe some come filled to capacity, while others don't have much liquid. I think the variability is not uncommon with pre-filled cartomizers from anyone, although I've never seen any comparisons.
There's a lot of e-liquid vendors who supply some pretty good menthol flavors, and numerous threads on the subject. Do a search on something like 'Best Menthod' and you'll find them. Refilling is definitely a lot cheaper than buying new pre-filled cartos all the time.