As nipping goes, IME, dwarf love fleshy LPS. SPS, left alone for the most part, but lesser PE. Haven't had any issues with zoas or clams.
As far as mixing.... It can be hit or miss, and can end poorly. Have to have a back up plan (( hoping to sell it, or take back to an LFS, is not a back up plan, IMO )) --- which means having another dwarf free tank to move one of them into.
For me, I currently have a coral beauty, flame and multicolor in my 65. The 3 of them being together for 3 plus years now. The coral beauty and multicolor were together an additional year (( bought a townhouse, so I moved fish around during the move )).
In my 75 I have a flameback and venustus, been together for about 3 months, no issues so far. They will be moved into my 210 when it is finally set up.
In both cases I used an acclimation box.
The venustus was in the 75 first, the flameback was in the box for 7 days.
With the 65, the coral beauty and multicolored were there first. The flame was added after spending 7 days in the acclimation box. Was some minor casing at first, but never a torn fin.