The way that I have the entity system coded does allow enemies to go after other specific enemies, I just haven't implemented any yet because it would be extra animation work (+ the first area is already meant to be kind of easy, and that would make things probably even easier).
As for everything else though, a good portion of what you suggested is planned to some degree. A Cursed Forest (ghost enemies / sort of living latex equivalent bog creature) and Slime Cave are both planned as early midgame areas, and while it might not be a factory, there is a location planned with mechanical enemies. There's likely going to be an area that's heavily plant themed either in the next update or the one following as well. Additionally, one of the main 4 bosses' areas is going to be bug themed, so that's a checkmark for insects too.