It's a cool idea. The post-Plantera dungeon is quite hard and has various enemies, the Lihzahrd does not. These are great opinions, but some of them should be rare to avoid being overwhelmed by these traps.
I like your ideas. Some could be slightly changed, but there's no need. I've a suggestion about that rotating trap: instead of dealing damage, it would knock the player back. It would be often near traps and shields won't protect the player from them.
That sword is also good. Very powerful, but extremely slow. Can they be buffed? I feel that buffs would make this weapon deal very huge damage, but its very slow speed would probably make it hard to use as and advantage.
Anyway, great idea.