That is quite a wide range with your budget and you will definitely see a big difference in places priced at $400,000 and those going for $1,500,000. Given your desire to be within walking distance to bars/restaurants and prefer a loft/open style place, Downtown San Diego (92101) is calling your name. As with any neighborhood, there are pros and cons and it's important to be aware of them. This is where a San Diego native and consummate business professional can best assist you. Another area that could appeal to you is Encinitas as the parameters you mentioned can very well be met.
No matter where you decide, please make sure to do a trial run on your commute (try driving it at different times) as San Diego is such a popular place and with that, unfortunately, comes some traffic.
At any rate, there are lots of great options out there for you and you should be super excited to be making your move to America's Finest City.
Chad Basinger, REALTORÂ®, CPA, CFPÂ®