So I'm trying to clean up my MISC menu items as it's becoming a nightmare to sort through all that crap.

I noted that the tubes I got in the Cambridge Polymer Labs are flagged as quest items and I can't drop them. Note I've already made the special piece of power armor using the machine in the labs. As far as I know I can't use these items anymore, but it's not letting me drop them either.

Is there more I can do with these things or is it just a bug that I still can't drop them?

Thanks.

Less a bug than an oversight, I think. Same problem here. They don't have weight, but it clutters the inventory. Like the holotapes and stuff from Vault 75.

Have you tried transferring them to a storage container (instead of just dropping them)? I made a crate in my home base and transferred a bunch of random misc that I didn't need anymore and didn't have any value (notes, holotapes, etc) into it. But now that I think about it, I don't know whether any of those were "required" quest items. If that doesn't work, I think you're stuck with them. Would be nice if when you were done with the related quest, they could move those items down to a grayed out area at the bottom of the misc list (like they do with completed quests in the Data section). You could still click on them and examine them later if you really wanted to, but they would be out of your way.

Similarly, why the hell did they remove the keyring from Fallout 3 and NV?

seriously. instead keys become invisible when I'm transferring to a container but it doesn't help when I want to just listen to a holotape or play a holotape game.

It does tell me some items are flagged and separated though so it won't be hard to fix in the future either by bethesda or modders.