I'm 28, my S.O. is 32 and works remotely as well. We live Downtown in Gaslamp and we love it here!!! There is always something to do and stuff going on. There are bars and clubs, but also museums and lots of places to go and chill. You are centralized and can walk to Balboa Park, or Sea Port Village, or even Little Italy no problem. There is no beach in walking distance, but you could easily ride a bike or even get an Uber or lift for cheep since the closed OB is that's far away. (Obviously I am in love with Gaslamp, so take that as you will)

Personally I like OB when it comes to close to the beach. The vibe there is very chill. Lots of surfers if you are into that. There is an awesome pier and a ton of places to eat. OB also has really cool tide pools that you acn explore and see little crabs doing their thing. (My favorite beach)

I used to work in PB and I hated it!! I would be fallowed by the transients in the area, it's a bit crazy there and I even had a stalker. (I know that that is just my experience and there are a lot of people that I talked to there that love it!!) It's basically a college party town. Where I worked we helped a lot of foreigners that were there for school with those finances so you do get a lot of diversity in the area. As far as my average Joe customer in the area it too was very diverse from older people who have lived there practically their whole life, to young fresh out of school and getting into there first place kind of thing. As someone already said it's a 21st Bday kind of place. The business owners there are very nice. (I personally wouldn't live there but as stated I have my reasons.)

Mission Beach can get really busy, and it's very close to PB and with my personal experience I don't go there often. I do know it can get busy in the area with Belmont Park being there and even mission Bay and you have PB beach easy to get to.