Somehow I picked up a Giants Toe and an Alto Wine that was tagged as Quest. This is very frustrating as I can’t use any of my collected giant toes in alchemy and 15 bottles of Alto Wine = 45 pound of weight....

Do you have the Unofficial Patches? I think they fix this issue.

Sounds like you've been drinking with a guy named Sam. I picked those items up after waking up in a Temple, there is a note in there somewhere which helps explain why they are quest items. If you finish the questline with Sam and pick up the prize it should un-flag them. Don't know how to unflag items with console, but it's probably simplest to complete the quest.

Ahh, yes, finish the quest they are for and they will go away. It's a great quest.

Don't need to worry about weight. Every quest item weights 0 while they are considered quest items.

The weight is displayed on the item but does not count. Try to put everything inside a chest and check your weight

Wow, thanks... that was an awesome quest... Since I play with Frostfall hardcoe it was kinda nice getting a free trip to Markath from Winterhold, and then a free trip back to Winterhold after I had collected the stolen books for “Hitting the Books” quest... perfect timing and saved me a lot of riding...

And Sanguine’s Rose... jeez that is a mid-level Conjurer’s delight...