I yesterday submitted my first run, but today i already did a better time. is it ok to submit this run, or should i wait some days, so i dont "spam" the moderators?

The run was already validated, so it isnt pending anymore.

I think you don't have to worry about it. Mods are humans, so if they have a box full of pending runs which need to be verified and they don't have time, they just simply don't check immediately. So unless you do incredible massive spam with submitted runs, it's ok. In the worst case, mods will contact you directly if you do abusive things :p

Most of the time, the mods will be happy to see an active runner of the game.

Also why do i never get a notification when somoene posts something in my thread, its basic feature all sites need