A lot of this is veering into the tangential for the sorcerer I think. The big problem is defining what the sorcerer is supposed to be doing. 3e's sorcerer was to allow concepts that the wizard was ill equipped to portray, which honestly is a lot, with a fairly different casting system. 4e made it all about innate magic somehow imbued into the character (Dragon Bloodline, Wild Magic, Mystical Storm Energy, etc). 5e tries to do both, but not very well, with a dash of metamagic. If you want to keep the sorcerer as a separate class, it needs to figure out what it's doing. Whatever that is, it's definitely supernatural however.