Everyone's a DJ nowadays

Does Twitch record what you’re doing for offset viewing?

You mean post-stream VOD?

Certainly some channels post them, but not all. So my guess is that it may be a function of whatever you use to capture your strim, rather than TTV itself (so much like you would use YT).

Whilst your set-up sounds like a good way to just give it a go, I imagine the quality will be quite "modest".

And personally, what makes TTV so much more appealing than YT, is the engagement with the DJ. Which doesn't mean necessarily replying to everything in chat, but eg some background on the track, an amusing anecdote about the time the cat shit in your record bag etc etc.

Just watching someone spin is pretty dull.

So if you do take it up more fully, I would prioritise that.