I'd like to put all the lights in my unfinished basement on one switch. I've got carpentry experience but only novice level wiring experience. Right now the lights are all on pull-chains. The electrical run that these lights are on also feeds lights in parts of my finished basement (stairwell and a finished guest room). I drew a diagram of the current wiring scheme below. Note, the partitions I drew under the wiring scheme are how I eventually plan to partition things (also adding a new finished room in the future). What I'm asking about right now is the area partitioned as "current unfinished space". I'd like to add a switch that controls all those lights (3 of them) but the switch shouldn't control any of the "soon to be new room", stairwell lights, or current finished guest room. Do I just need to put a junction box before the first light (and after the last) in the chain and run a wire by-passing the 3 lights from the stairwell to the guest room? Then from that same junction box, power the 3 lights/outlet in the current unfinished space? That seems to make sense to me, but wanted to make sure I wasn't making it more complicated than it needed to be (i.e. simpler solution?).
Also, assuming that's what I have to do, I'll need to re-wire that electrical outlet so it's not turned off/on by the new switch as it's currently wired, right?
This is all unfinished space so obviously I have access to the walls/ceiling. Any help/advice would be appreciated!