As ds says it would be best to have a monospecific tank where you kept either zoos,
shrooms, & leathers or
SPS and
LPS. Leathers put out a toxin that the
SPS won't tolerate well. Zoos &
shrooms can kill an
SPS if they're allowed (or if they disobey and do it anyway) to grow near the base of the
SPS.
SPS and
LPS seem to do well together except for the fact that most
SPS require high light and most
LPS like lower lighting.
In each species there are some that are known for their sting. Some worse than others. I think it along the lines of when a touches b, a dies. If b touches c then c dies but if d touches b then b is toast.
IME...
When they touch:
Frogspawn will kill a candy cane
xenia will kill a monti cap
platagyra will kill a favia
milli will kill digi
most other acros can coexist peacefully with digi
frogspawn & torch will coexist, touching even!
Hydnophora is best left in the sand by itself though my microconus & my green hydnos seem to do well together, touching even. If it touches most else it will probably kill it (though I've had frogspawn fall on it with no ill effect to either).
I think you'd do better to discuss what you like about certain corals and which ones you'd like to keep. People might then be able to tell you which ones you could keep together and which ones need their space (platagyra send out sweepers, as do pavona and bubbles ...).