Insurance is suddenly dropping me due to the buildings not having a sprinkler system.

I've been at 100% occupancy for my small spaces for the past 5 years.My only feedback is that $2 per month per sq ft NNN seems really high to me, but each market is different. 

It's difficult to understand your question.

But we manage a lot of units and unfortunately cannot possibly manage 70+ units with free software!

We seem to be free of that here.

It used to be quicker.

There's a high chance that you are feeling FOMO from the returns in public markets, sell your houses for a loss, pile into stocks, and then see mediocre performance while real estate heads back higher again.I see this, and similar actions, play out over and over.Personally, I'd stick with the real estate rather than selling it.

It would also be nice to know what you plan to do with the property once it is built. 

If I were to purchase (at a higher price) then the taxes I pay would be very different from their taxes.

If you are looking for property in San Diego that is going to have good initial cash flow, you are going to either have to identify an obscure value add or expect to spend a lot of time and effort to find good off market purchase (most off market offers are not great).