I just wanted to get feedback on two topics. Would it be a problem if I doubled on trumpet? And what are your opinions of a trombonist screaming(I have been developing my low range as well as my tone and improv. so I`m not neglecting anything.

Nothing wrong with doubling on Trom. The mouthpiece will take a while to get used to, and when you switch back the first time, you will think the trumpet mouthpiece is a pea-shooter..about the size of a pencil on the chops. You get used to it, so just always finish off the practice by getting back onto the trumpet..your brain and chops will adjust in pretty quick time.

Good luck.