Presets, no question, use them. Patterns, I would try to make a good-faith effort to tweak and/or augment. For “occasional live gigs” it’s probably fine. There are any number of DJs who basically play other people’s music with a bit of crossfading and filtering. Technically they should be paying royalties but so should every tiny coffee shop that has a smartphone playlist, and neither do. I would think that, as a matter of personal growth and pride, you might want to move towards original material, but you don’t need to rush, or agonize on the way there.