If it were me, I'd toss all those aforementioned fish into the 300 right now so I could shut those tanks down, but I'd transfer the shrimps to another 'holding tank/s' until the NH3 is gone. Shrimps won't take any NH3 like fish will.
I wouldn't expect to see any NH3 in a system of your size, but no problem being safe, ya ?
The # of fish you listed is a drop in the bucket for your tank size. But, keep up with your MB7 and testing. If you forget 'cause it's been awhile, Ammo can sneak up on you fast. It'll burn critters within hours so be very diligent.
If you're nervous, extra aeration helps the fish, and lots of testing is a must
I use an Ammo Alert in my QT and it's helped tons while I'm running hypo. Each time I see NH3 trying to climb I add a bit of Seachem AmGuard ('cause I already own it) and it works wonders. This allows me time to setup a WC and test NO2/NO3.
I say dump those fish in and enjoy !
And don't forget to snap some pics !!