Looks like the OP got his questions answered, I hope.
Funky taste after a while? Primer pull a time or two and take off again.
Dry on cotton top inside the carto? Don't worry as long as your hittin' good.
Hole size, 2 or 1, VG, 50/50 all answered very well.
Here's what I do prepping for a tank:
http://www.e-cigarette-forum.com/fo...-tank-discussion/268036-jig-saddle-valve.html
After pop (thru), one full turn per hole.
2 holes for 85/15 to 100% VG and
1 for everything else.
Prime well. I drip at angle and thermometer flip, repeat.
Fill the tank.
Primer puff and watch for air bubbles, and then just once in a while as needed.
-On the tank.
I guess the only reason they call them DCTanks is that's what carto they send w/ it!
I bought 2 tanks the other day for less than $10 w/o the cartos. myvaperstore.com I think
As long as it works fine, cheap is a plus.
Like was already mentioned, match what you need.
Like countless others, I'm running 1.7 SCs on my 3.7 device and 2ohm DCs on my VV.

4 mths in for me, so I'll be a noob for a while yet. This is just my personal exp.
Glad the ECF is there and everyone on this thread too.
Thanks