1 Yes, I trust them more than Google
1A It's very little, mostly down to updates, network check, sntp, ect

2 Yes, he has been a prick at times but he's never done anything malicious
2A The code is open, if there was malicious code we'd know
2B He's contributed code to AOSP, so you're trusting Micay regardless
2C He stepped down from the leader of Graphene. I think the swatting put him in a bad place and I won't defend his actions but his actions are fairly irrelevant in evaluating the project