I reinstalled Skyrim today and the same bug from every Bethesda game is back...the buffs that were on the items in my mod are permanently on my character now. Is there an easy way to get rid of them? The only thing I can see to change is carry weight and resistances using player.getav.

sounds like mod issue, you should contact the modder for assistance. probably some uninstaller and/or steps.

I am the modder. It's not an issue with the mod, it's an old Bethesda bug. If you have magic items in a mod, and delete the mod while your character is wearing the items, the buffs will stay on him permanently. I was really surprised to see it return in Skyrim as it's very easy to do and supercharge your toon by mistake.

maybe another to mod to track all active buffs on player, to identify their source, if source is not valid, then removed the buff?

I guess i don't understand how you think this is a bug?? It is Exactly how it would be in real life... i could post many many instances where this is true, but i will just use the easy to visualize.

You have a light switch. You can turn this on and off. now imagine that you turned it on, removed the switch. does it not stay on forever?(assume the Electrician leaves it in the ON state.) Of course it does. With no way to turn it back off. you would need to put the Switch back to have control.

This is not in any way a bug per say. Most mods will tell you that you need to remove anything the mod adds before removing it.