Hi I was just reading your post from start to finish. I hope your bf is doing OK.
I may have a little insight into the snails issue. I recently purchased 3 sparkling gouramis and i swear I saw an almost immediate drop of snails in the tank. I think they eat the small ones. I can't prove it but i think that's what happend. I have some ghost shrimp there and they'll even go and bite those even though they were bigger than them.
Well the bad news is that my large gourami (i had 3 sizes as well) bullied the other two and eventually they died after about 1 week or so. He ( i call him he) is still alive and thriving apparently. not shy at all. anyway... just my two cents.