Wow! It sounds like at least ONE of your gourami is settling in very nicely. That must be very entertaining to watch, lol! Please try to snag some video of it - even if it takes forever! I'd love to see. It'd be cool if you ended up with a pair. . .
Hooray for the little loaches feeling more at ease again - very, very good stuff. . .I hope you manage to up their shoal eventually, but good to know they're doing well with only themselves.
I hope your Sengal is okay :/
It sounds like things are going very well over there. . . I can't IMAGINE doing a water change that immense. You know. . . your water-change is my entire tank?!