Draco, the thing with the story holes is this: they didn't elaborate on any of the plot, the entire way through the game. It's not like they just missed a few things here and there. They missed everything. There was no supplemental plot development at all.

The framrate hiccups are very rare, and all that happens is that the action will skip for less than a second and resume to normal.

As for Soul Reaver, there's no way in hell you can be fighting that boss already. If you just started the game, and you're already fighting Dumah, then you're using a cheat device or codes of some sort. You skipped all the way to the 2nd-to-last boss.