To begin with, thanks for reading the "Read before posting" topic, I was wondering if anyone was reading it for yours questions:
1) autocompletion, nope, not yet, but you can use codingameSync (search on the forum to find the topic) to use an external editor like Atom or SublimeText which have autocompletion.
2) Not yet either, you can't post full code on the forum because some users will just copy paste the solution without trying to solve it by themselves. CG is planning to do specific topic to share which will be only accessible to people that finish 100% a game.
For 1) and 2), CG is currently redoing its IDE, so maybe the feature that you're looking for will come soon In the meantime, keep coding!