New tank mates for my bristles... any suggestions?

I havn't post on here in a while! I have my 125 tank now looking empty!

Its far from empty but all I have in there now is
4 Peppermint bristlenose
2 albino's
1 small common
1 adult common

1 humbug, hes as soft as tissue!

And I have just added my sisters male betta as he was being neglected by her!

Ive been advised to remove the humbug, being told he will harm the other cats but Ive left him in there because the other cats seem to enjoy sharing a cave with him!
Strangely enough, the biggest male peppermint is always squished in with the humbug... when there are 4+ other empty caves around the same area! I never see them fighting and none of them have marks or any signs of aggresion so for now.... he stays. (although i find him freaky so hoping to rehome him soon haha!)

I have a small group of fish I would looove to keep, no idea why, Ive just always wanted them!
Clown killifish
bee gobys
melon barbs (they were labled that in my LFS, not sure of their proper names)


Will the bee gobys be ok with the betta? Im leaving the melon barbs because obviously they cant go with the betta=/


Also.... any other suggestions? I really like the markings on all of these fish which is what drew me to them.

Thanks in advance!