We then were able to go under contract with our future home a few days later.

It's a good move to keep things separate – set up a business checking account for your rental income and expenses, and maybe a savings account for unexpected stuff or future upgrades.

Projected equity How did you find this deal and how did you negotiate it?

If they are providing value you can pay them as a project manager.

Looking for some insight if I should wait to purchase in the hopes of more multifamily properties becoming available in the future, if I should make an extremely low ball offer on what's currently listed.

I'll use that to re deploy into another rehab project down the line. 

By taking steps to increase your current cash flow, you may be able to build up your capital and potentially consider expanding your portfolio in the future when the numbers are more favorable.Ultimately, it's important to carefully weigh the risks and benefits of any investment decision and consider all potential outcomes before moving forward.

Full details on the project are available including project description & costs, 3-year income/expense spreadsheet & photos. 

I found a property that cash flows around $100-$150 in Bakersfield, depending on the interest rate, but I am wondering if it is a good idea to take this and run with it as a first rental, in order to be able to cash out refi in the future to be able to put a bigger down payment on a mult-family property.

If I build an ADU, can I split the lot later in the future or will I no longer be able to after the build of the ADU?