Assuming the Oakland rental market continues to remain stagnant/competitive with newer buildings going up, is property appreciation the only way to increasing wealth with my building?

I continued paying what I had paid before, with the additional money purely going to principal.The recast to a lower amount was purely to reduce my committed monthly payment to a point that I could get my property to cash flow if I had to move out (job loss, etc).

Many banks securitize their loans (bundle them together) and sell the loans to Fannie Mae or Freddie Mac, while continuing to service the loans, that is collect your payment.

If it's going to continue to be a 3 unit building, it would make sense to add another service.

I recommend continuing to learn pros and cons of each and determine which paths (I pluralize it as you should diversify even across real estate).

If the rules change then sell or use for a long term rental because the home values continue to rise.

Should you choose not to renew your current lease you will only have to pay the difference of the last month’s rent you originally paid. 1750-1495= $255.Current Rent: $1,750Increase: $119New Rent Rate: $1,869This increase takes effect the 1st day of November, 2023.We’ve been happy with you as a tenant and hope you continue to stay with us for a long time.

and for the record not here to bash, i know it has helped a lot of people and i know it will continue to improve. 

As far as I know the prices have continued to be stable or go up.

In fact, invest outside Calif for sure.I suggest you continue to rent and buy an investment property first.