If I could choose, I'd probably pick elf for the reasons you listed, and sorcerer because blowing stuff up is cool.
pathfinder
Is one of the sorcerer options the one which essentially gives you a mini fireball or is that wizard?
I'm not actually sure? I know you can get actual fireball as a sorcerer, but I've yet to play one in Pathfinder.
I'm not up to speed on Japanese cultural or anime concepts, but I thought the idea around Isekai was that you are transported into the game/story world. So, wouldn't that force you to play Human by definition?
It's your spirit that is transported to another world, not your physical body. There are a lot of stories where the character is reincarnated as a different species and even some where the mc is reincarnated as an object like a vending machine.
They are starting to get recursive too, where character from a fantasy world gets isekai'd to a different fantasy world with a magic system similar enough their magic knowledge gives them a huge edge, or their original world OP starting skill that they had severe social limitations on using doesn't in the new world.
I guess I sorta lump all the reincarnated and such all together and since ancestry has a fair effect on abilities I figured I would do it. I totally might be using the phrase wrong.