Firemouths - a little too aggressive & large for the mix, I think.
I double checked a Tiger barb profile (Badmans) - it specifically reports that they shouldn't be around Angels and there are comments leading me to believe that minimization of aggression by keeping groups is not reliable.
Nolapete- although i like scarface i miss seeing your festae pair. I heard Katrina destroyed them, did you get them to breed? That must have been a huge, mean male.
On the topic of Firemouths I would say it totally depends of the personality of the firemouth and it's probably not worth the risk. The female of my pair could live with any fish on the planet and never bother them (as long as she's not guarding eggs or fry) but the male of my pair would kill half your tank in the first night.
I wouldn't put tiger barbs with most sa/ca dwarf cichlids. Has anybod tried t.barbs with kribs? I would want to see the barbs reaction to a pair of spawning kribs:evil_lol: