#1 Depends on the person some may never get gyno some get it bad on any amount

#2 Again depends on the person but most will get a fair bit of bloat from Test E if your really worried you caould take an AI

#3 Ive never really heard of this im guessing just nervousness

#4 They will probly fade on cycle with water retention but as long as you do a proper pct and your diet stays in check that will change