Say I create a patch that edits the 34000FB1 record from a mod as an override in my new esp. I remove a mod in my load order and the original mod's formID changes to 33000FB1, but my patch mod is still looking for 34000FB1. How do I make it dynamic?

You don't actually need to worry about that. Your patch will automatically adjust. Form IDs are internally handled as 6 digit numbers. The leading 2 in an 8 digit ID are solely used for the load index number.

If you were to closely examine your patch using a hex editor, you'd find that the masters it lists show up as 00, 01, 02, etc. on down.

I'm loading it in TES5Edit and it's retaining its old leading numbers in the formID, and none of its changes propogate ingame because the original objects aren't being edited anymore.

Could you shows us a screenshot? That doesn't sound normal.

http://i.imgur.com/ireTq2B.png

http://i.imgur.com/B9npk3w.png