Not familiar with the San Antonio market, but I would recommend getting on MLS, craigslist, and FB marketplace and get an understanding of where in the city a lot of the flips, new development, and rentals are.

I have had ideas of developing senior living.

I do have some knowledge of the process of developing land as I work for a commercial general contractor in the area and I’m also a residential real estate agent so I feel like I have many pieces of the overall puzzle but can see the full picture yet.

Like you I know many large apartment developers that are just quietly slipping elsewhere.

And yes, with plans developed by the contractor's architect, they aren't likely to allow you to use their plans to shop around for another contractor with a lower cost.  

I have an R3 lot to develop in "Tony" West LA 90064.  100 foot frontage to the street and 150 feet deep.

I’m looking for ideas on how best to develop an in-town building lot I picked up at auction.

I'm having trouble calculating ARV because this is NJ and it's not a model development, meaning this home's structure is different than most in the neighborhood. 

The type of real estate development that I want to do in the future is Spec homes and apartments.  

Recently, my real estate agent let me know about a development opportunity.