Hi guys, I'm sorry that i need to ask few questions here, I'm just too lazy to search

I haven't heard from vaporshark yet but I just bought some wire to experience on first. And this is my first time getting into rebuildable
I bought 30 gauge ni200 and plumeveil 1.5v clone
I tried to read some pages, so I conclude that it's best to do with space coil with using the mechanical screw?
what size should the screw be?
I play around the steam engine, it's telling me that ni200 need many many wraps
what rda/rba should i avoid because it won't fit the coil?
I plan to use the plumeveil at home, and buy one rba to go
which one do you guys recommend? my budget is around 30 (lemo drop, subtank, kflv2 are on my list)
Some of the members here mention about tighten the legs really hard
what does it mean? like tightening the screw on the atomizer where the legs and the "hole" makes connection?
btw, i bought the ni200 from amazon, seller is lightingvapes but fulfill by amazon. 2 days shipping is crazy! ordered on Sat afternoon, arrived this morning 7am!