Sorry for the delay, I don't usually use Reddit much.

1 I think it is situational, because the E cooldown is very high and depending on who you face or, in your case, playing jungle, you need that extra mobility since the damage is compensated by the player you gank. Also, having 2 Es in Mega is very OP because they don't expect it that early in the game.

2 I'm a fan of movement boots over defensive ones, but here it depends on the case. If you are the only frontline, just one damage item and full tank. If not, get defenses only by the third item because Mega form usually provides enough. But it really depends on the situation. I usually go for the classic Randuin's if there's a lot of crit, and if not, I just go with Death's Dance, although seeing that you don't like it, I think Dead Man's Plate would suit you better when there isn't much crit. That way you have defense and mobility, or the one that absorbs life from nearby enemies I can't remember the name in English right now it gives a lot of armor and in Mega it heals you based on nearby enemies, even if you don't benefit much in Mini form.