Solips don't even remotely need mindstar mastery (which is honestly kinda' wasted on 'em... it's got some nice defensive utility but not much beyond that for a ranged class, and if you can get mindstar mastery you can probably get fungus or AM instead.) or antimagic, though losing fungus access stings a bit. It definitely helps 'em, but it's far, far from necessary. Skeletons are still ridiculously tough to kill and provides that sexy debuff duration reduction, which makes them an incredibly solid anything-but-wilder. The heavy shielding goes a long way towards making up for the fungus loss, t'boot.
Ghouls are alright, too. Extra mobility, extra toughness, nice heal, solipsist speed bonus helps offset the ghoul's malus. It's pretty decent. S'worth noting I value ghouls pretty highly, though... the speed penalty makes people crap on them harder than they really deserve. It's functionally not that bad and ghouls get some incredible bonuses.
Yeeks are... honestly, only 'alright' solipsists, from what I've seen. Good, but I'd rather play something tougher. Yeek solipsists have the same squishy problem as all yeek builds do, and while solip tankiness helps ameliorate that quite a bit, it's still there and a problem compared to other races. Best solips are probably thaloren at the moment. Saves boosts, that sexy sexy resall, nice buff, and better meatshields. Even with the nerfs, though, it's pretty hard to go wrong with solipsist anything.