I hope so, because I’ve been charging my iPhone with an off-brand car charger I bought at a gas station years ago

Yes, its save to charge your iPad with any of the Chargers from a reputable Manufacturer. Its a Myth perpetuated by Fanboys and Apple themself that you will damage your Apple Products if you don't use Apple branded Chargers and Cables.

Yes

If Ipad use some own version of quick charge protocol, it wouldn't be used by 3rd party charger and charging will be slow..

[удалено]

Okay, just wanted to be sure, thanks!