is there a class that allows this? would like to weld em so i can get rid of all the brackets,bracing and everything and just use window nets but idk if this is allowed

Drag cars require doors that open and windows need to be closed. If you want an open body car, you can't do it in a door car. You need to run an altered or dragster. Even a convertible needs the top up and windows closed.

About the only "class" that requires welded doors is oval racing because of all the bumping and grinding they do, they don't want the doors to open when hit.