This all looks excellent to me so far, and I think your tectonic boundaries make sense as they're placed now. A couple things I might have done differently, such as adding some more mountain ranges to the north of your big orogeny in the center of the continent, and maybe putting the plateau/escarpment closer to the coast where the small continent is rifting in the south. But overall I think it's quite plausible.

When it comes to inactive orogenies such as in the north, I suppose you've a bit more room to play, especially since they tend to get warped and deformed by subsequent tectonic processes. Of course, the best way to figure that out would be to map out the tectonic history in GPlates, but that all depends on how much time you want to spend with it! I think it looks alright as is, though perhaps I would put at least one more defined mountain range (such as the Appalachians or the Ural Mountains) rather than one big plateau. But again, overall it looks great!