To answer your first question... yes.
A Kick or Kick 2 adds 15mm (plus/minus a few tenths) in length... the same "jump" from one battery size to the next. So, Kick, + battery + the next length up battery tube from the battery size you're using = fire (of the regulated variety) in the hole.
A tele has no issues with 18350 or 18500... but if the center tube isn't long enough, you can't accommodate a 18650 and a Kick. There are teles that come with or have available a longer center tube... just to run 18650/Kick.
Some fixed tube mechs come with an 18350 tube and two 15mm extenders for the longer batteries... so no 18650/Kick. Some come with 1 each of 18350 through 18650 tube, so again, no 18650/Kick (but clean lines with any battery)... and then some come with, or have available, a "Kick tube"... which is nothing more than the 15mm extension tube, I first mentioned.
To answer your second question... The man concern with a Kick, is getting a good ground contact... which is why the Kick 2 has two long spring loaded ground posts.
A mech with a "loose" tube, or where the kick ground posts only make contact with a (larger ID) female threaded portion (most tele mechs)... can be problematic. With the original Kick, and even still with the Kick 2, people must improvise ways to offset, shim or or otherwise push the Kick ground(s) more firmly into the tube.