Should I export from 2 apps

Right now I am using SC just to put text in…I usually put all the clips end to end in Quicktime since it plays the clip anyway… so I am exporting from Quicktime as mp4 and then again from SC using the YouTube preset as mp4…
Am I degrading the video by doing that twice ??? what do you think?

Depending on your export settings, probably yes, but just barely.

You shouldn’t worry about it, youtube is converting your video again and it intentionally loses a lot of details to make the file size smaller so in the end you won’t actually notice a difference from 2 exports.