I think Rick's frame of mind right now is shattered. He never wanted to be a leader, but took on the role somewhat reluctantly. Watching someone bash two good friends' head's in with a bat would be pretty traumatic. He fully blames himself for it I'm sure and the possible follow-up threat of having to cut up his son or what they could do to Carl, Judith, Michonne, etc. has him scared to death. Doesn't mean he won't fight back at some point - you can see he still wants to in those scenes where he's gripping the bat - but it wouldn't be realistic for him to put up a fight right now after all that.
As a cop, I assume Rick has a better idea than most of how lying can go wrong. I don't think he remembered the ledger - if he had, they should have destroyed that immediately. But hiding stuff, lying, fighting back means someone else gets killed in front of him. As for Maggie - wasn't it the preacher who said she was dead? Either way, I think Rick gets that Negan takes whatever he wants. He showed some interest in Maggie when they first met, so hiding her away saves her from a fate worse than death. That one was worth the risk.
I did like how Rosita immediately figured out how to get more guns. It's a good bet that more undead have them, so not a terrible way to rearm themselves. Eugene can make more ammo, which Negan still doesn't know, so Alexandria still has some surprises waiting. I'm not sure ALL of the guns were inventoried anyway, so won't be surprised if some are stashed away. What about the gun Carl pulled on Negan's guys? And didn't Rick or someone hide a gun out by some white house when they first arrived in Alexandria?
I'm with Scock though - an RPG waiting at the gate for Negan could have ended things quickly. His troops wouldn't know what to do with themselves. I guess using the RPG again against Negan would be lame story writing, but that would have been a cool way to turn this all around. They did go out of the way to let us know that Negan came earlier than expected, so maybe that threw a wrench in some plans to fight back.
I really like the contrast between Rick and Daryl in this situation. Daryl could have it a lot easier with no effort, but refuses to give in. Rick gives in 110%. It's going to be interesting to see how this all plays out. Will Rick just need some time to heal, then hatch a plan to fight back? Or will Daryl inspire the other saviors to turn against Negan with his defiance?