I think we could do it either way. The layout I did most recently seems like it would lend itself better to not being trees, just because of the way the rooms are shaped, but we could use it if we wanted to and I think it'd still work. I like your walls better though. But for the boss room, yeah, trees definitely.
That golden kingdom game is really interesting. If you scroll down, they're using the town tiles from King of Thieves. They're also using my big boxes and I think my Garo sprites, and I thiiiiink the Japanese style building they have if you scroll way down is a recolor of one Leduardo did some of and I expanded, but they may have edited the Shopkeeper's house at lake Hylia themselves. Those tiles might be cool to work in with stone buildings also for the Shiekah Fortress.
I know all the sprites I've done I've hard are free to use, but it makes me wonder, who originally did the town tiles for King of Thieves? Was it King Mob?