ccs
41st lv DM
It is no secret, an utility-focused dumb -if not also feebleminded- but very human-looking sorcerer(ess) who fights with spears has a talking raven familiar and goes everywhere on a floating disk dragged by an unseen servant.
Core only possible in 3.0 to PF.
How do you get the Unseen Servant to drag the Disc in 3x? In PF? Especially core only?
Concerning DMing/playing with the same people....
Well, count yourself lucky, I do what I can with what I've got..
No, I'm not lucky in that aspect, I'm in the norm. You though appear to be unlucky....

If there's people who're willing to play Vampire in groups, & are willing to play the occasional D&D game, have you tried to get a few of them to form a consistent D&D group? Even if you only play on the occasional basis?
When everything is generic enough, Roleplaying makes the character. But 5e is not that generic, and more so with the sorcerer and wizard.
5e is no less generic & flexible than any other edition. The whole game (D&D of whatever edition) is built upon making things up & adding them to your games. The printed rules are NOT the be-all/end-all. Though you will definitely find DMs who're afraid to do so. Especially ones who grew up with 3x/PF, a constant barrage of books & worse constant doses of errata. They've been conditioned not to think for themselves.