Thanks for all the great replies! Good info all around!
I spoke with a few friends who completed the Camino and looked elsewhere online and in guidebooks. I think I want to start in St. Jean, walk for about ten days or so (plus or minus a day), perhaps as far as Burgos, then catch a bus to as far away as Sarria and finish the Camino walking from there, and then perhaps go on to Finisterre if I have time. Does this sound like a reasonable plan? Or am I messing up by essentially skipping the middle portion by taking the bus?
I say this because I think I really would like to start in St. Jean, experience crossing the Pyrranees, and then savor Basque Country. But I also really want to finish at Santiago and get my Compostela. I understand that I wouldn't be with the same people throughout, but I'm OK with that. I more want to experience the culture, the towns, and have a more meditative singular experience for my first Camino. But yeah, trust me, if I had four weeks, I'd do four weeks. The time constraint is the only thing forcing me to think about where to skip via bus in the middle.
Also, I'll now be flying into Bilbao, then flying out of Santiago de Compostela, for what it's worth.