I moved your post to the correct forum, the Mixes, Music and Shows forum is just for that. Your question belongs here in the DJ Booth.
Is it ok? I’d say no, for at least two reasons:
1) You only DJ with music you bought (not Spotify, not illegal downloads and not Youtube).
2) The initial quality of a Youtube track is dubious at best, then converting it to MP3 won’t do anything for the quality of the track. Hence it pays to pay for your tracks and preferably in WAV or other lossless format. You can then process the track and only at the end of processing convert to highest quality MP3 or other lossy (AAC for example)
.
