Yes, we're looking at splitting out some of the tables like the user_profile table.
As for smarty. We're actually looking at replacing that as well, and possibly just going back to the way we did templating in the 6.x series of UBB.threads. This style of templating is still used in the admin area control panel.
Initially we were looking at using the caching of smarty, but it really doesn't fit with the software. So it's definitely extra overhead that we really don't need.
When we do the UI update we'll have to modify every script/template, so we "might" phase out smarty at that time. Nothing set in stone just yet, but we'll see.
