Good call on the Keyholes, they WILL get battered otherwise, I have 2 in a 400l tank with a full grown festivum and a pair of Curviceps, only reason i see them is I also have a small shoal of rainbow dithers in there along with a shoal of denisoni barbs, otherwise i think they would hide away all the time. You have much more agressive species than me and I doubt they would stand a chance especially during feeding!
it will all be fine,hopefully my carpinte can stay in with the sevs, if not he can have the 350 to himself. my firemouths are going to have to go though, the have paired up and keep going after him, i think my texas likes winding them up though because he makes a point of going over to them, he will give the a little wiggle dance and it all kicks off.
i have to grow him to full size. even if he ends up with a 5 footer to himself. lol
i think hes/shes going to grow into a good looking fishy