Don’t know the development well, but think that SM is a decent place to buy. We’ve been keeping an eye on some properties there, and you seem to get a lot more for your money vs. Carlsbad or Encinitas, yet it’s still very close to those areas for shopping, etc., not to mention the proximity to the 78 all all the shopping along that corridor.
Haven’t been to Sunset Park yet, but have heard great things about it.
Sounds like you’ve found a great house and lot for your family. If you can comfortably afford the **total** payments, including PITI and all the Mello-Roos, I think it’s safe enough to buy there, especially if you’re getting a mortgage, as rates are not likely to go down much further from here.