UCSD has a solid engineering program with great industry connections, wide alumni networks and cutting-edge research opportunities. The defense and aerospace industries in San Diego are closely tied to its MAE department, which is the original department of the Jacobs School of Engineering. I’d say of the six schools you listed, Purdue and UCSD will offer the best career building opportunities. Additionally, UCSD is a ten hour drive or a one hour flight from the Bay Area, which sounds like the right distance for you (farther than UCSC but closer than Northeastern).
While the student:faculty ratio at UCSD is a little higher at 19:1, it doesn’t feel large by any means. Faculty are easily accessible if you put in the effort to meet them, whether that’s during office hours, engineering social events, or campus programs like Dine with a Prof. If your priority is to develop connections with professors, and you put in the effort, it won’t be a problem.
The campus is beautiful and located in gorgeous La Jolla. The school of engineering has some really cool public art installations. The college system makes things interesting, although I’m personally not a fan of Sixth College. It has the added advantage of being in San Diego, which is a fantastic city with tons to do. While the party scene isn’t amazing, anyone who’s even slightly social will be able to make friends, find parties, and have fun. If SDSU gets a 10 and BYU gets a 1, I’d say UCSD is a solid 5.5 or 6. I’d visit on Triton Day to see if you’re feeling the overall vibe.