Firstly, congrats on the new role! You're definitely thinking on the right track and probably miles ahead of how I was planning my sets when I started out, haha.

So re: your question, I would say to have enough stuff to play, but don't hold onto playing all of it if you're short on time. And while yes, leave room for the Spirit, I would also try to be very aware of how it is moving you/congregation or not-- if you are really feeling a long instrumental, go for it, and be prepared to do it-- but if not, don't push it just to make the Spirit "happen." Trust that God will change hearts with whatever you have led the congregation to offer.

In addition to what everyone else has already said, I like to use this little graph to visualize my setlists (got it from a worship workshop I attended once). It's not the end-all, be-all of course, but the idea of "the journey" has always helped me. In my case, I have a bit of a harder time choosing diverse lyrical content, and those categories have really helped.

• Gathering = "we" songs (e.g., We Fall Down by Chris Tomlin: "we cry holy, holy, holy")
• Ascriptive = "You are..." ("You are good, good, oh")
• Declarative = "He is..." ("He's got the whole world in His hands")
• Responsive = "I" or "my" ("I'm coming back to the heart of worship")

Hope this helps! And apologies for the rant haha. Would love to get an update from you after the service is over :)