Quite possible, but at least for the brushes that limit is very high, so I don't consider it a problem. I've seen people have a few hundred in one palette (how sensible that is, is doubtful to me, anyway). Perhaps this is more a limit of rendering the preview icons in your case.... As for the actions - I think you can only have up to 32 sets, each containing 32 actions, but likewise, that doesn't strike me as being limiting at all. but what do I know - I'm certainly not a power user...
Mylenium