Just my $.02, but based on your stated priorities above I actually think Temecula/Murrieta might be a great fit. It definitely has a community feel (especially neighborhoods like Harveston, etc). I have trained for a number of triathlons while living in Temecula, and there are lots of places to cycle, run, etc. Also a lot of golf courses (Redhawk, Temeku Hills, etc.), and are fairly reasonable as well.
There is actually a ton of infrastructure now, and mostly you will be going to SD for stuff like major sporting events, the beach, or higher end shopping. There are some older, quaint restaurants in old town, the farmer’s market (also in old town), and a wide variety of chain restaurants.
House for the money is a no brainer. Temecula / Murrieta is way ahead. You can also get a lot more yard in many neighborhoods than often available in SD. The realtor we used to sell our house there is outstanding – extremely proactive and an amazing resource (he is even working to find us a realtor here in Charlotte to sell our existing house). Let me know if you need contact info.
Traffic congestion on the 15 is mainly around rush hours, although I’ve noticed a little less severe with the gas prices. Also, traffic is pretty tough on the 79N/Winchester Rd. Proximity to freeway can reduce a ton of commute time, as I’ve been stuck on Winchester for over 20 mins to go just a few miles.
DeLuz is actually a pretty good recommendation. It’s still near south Temecula so you don’t feel too far out. You may also look at the La Cresta area, which is in the mountains just north of Temecula / Murrieta. It’s a bit more removed, but beautiful and lots more spacious. I’d google Tom Metzger in Fallbrook and see if that is someone you feel comfortable living near.
Anyway, hope this helps. Based on the priorities as you laid them out above I think Temecula/Murrieta might be your best fit. Please feel free to ask any questions if needed.