Bump on the front tire rim

Am I reading you right, that the scrach mark is on the metal rim, not the tire? If on the rim, and it's minor, there's probably no problem. If he hit it hard, he could bend the rim, but you'd feel that when you hit high speed you'd get more vibration than before. If he hit the tire and you get a bubble in the sidewall (run the flat of your hand around the sidewall and see if it feels like a bulge where he hit), then that's a place of weakness where the tire can blow out, and you should replace the tire. Very soon.

If you can hear screeches while driving after a bump like that, it is probably nothing to do with a mark on the tyre, but you should get the steering geometry checked.