Given some of your complaints, I don't think 1e will fix them. Despite our collective positive memories of it, its honestly a hodgepodge of weird subsystems etc. If you're players have trouble with remembering how bonus actions work....I don't think that it will get better with all the weird mechanics.
Personally, if you like Dungeon World, I'd go for it. There's even other Basic-er Apocalypse Engine games out there for dungeoneering. I can't imagine that conversion couldn't be done on-the-fly. (Especially since all the rolls are player-facing, you only need to come up with HP for the monsters.)
I'm also not so sure that you couldn't run a stripped-down version of Fate Accelerated. Again, conversion on the fly is probably okay.
Another game that jumped out to me is Strike! Its got a super-simple system using only a d6, and detailed tactical combat is totally optional.