Few Qs... info would be great

News

Ok, I started playing this what seems like a long while ago, when we could only complete up to Drake in history. Got caught up with classes, stopped playing, came back and played a Sieg for a bit, didn't really do much, beat all the stages on history, that's about it. Now playing an Arien, getting close to LV70 (never rbed before, only started the bonus stages for the first time about a week ago), and going through the raid stages solo to get the RB book. I'll admit I'm sort of clueless about a lot of things in game, I'm picking it up, but there's a couple things I'm not sure/curious about.

First, heard myth equips don't work in stages? I guess this includes bonus too. Or that the stat bonuses don't work. What's the story?

Second, sort of a follow-up, to those in myth stages, what equips do you regularly use/suggest for stage/bonus? I got my hands on 4 pieces of an LDrake set, but had less than 2k hp at LV65+ and the def wasn't exactly great. Recently switched to a full AWD set, and it's a lot better, overall. Just looking for ideas..

Third, seems like people that start myth parties are looking for people with say 3k+ or 4k+ strength. I can see this in myth, with the stat bonuses the equips give, but recently I saw the same thing for bonus stages, except it was 1k+ strength. I don't even have 300 strength at level 69. How is this possible? Stat dyes? Rebirths? Insane equips?

Yeah.. it all ties together, sort of.. but hey, any answer is appreciated.