So, you  each have the option of taking debt, adding your own cash, or doing a partial exchange and purchase less than you sell (and pay tax on the difference).The guarantor of the mortgage really doesn't matter. 

Adding a negligible amount of tax revenue through income?

Phila will always be a large metropolitan area and have demand.If you want to talk about Phila let me know, I'd be happy to do so.

Can adding a bedroom and bathroom without increasing the square footage of the home still increase its value?

I had to see it for myself.Advertising VacancyI posted the ad on almost all platforms.

But it's like a one-stop shop and they set you up with all the ads.

Your return on equity is very low based on those numbers provided so yes, some action needs to take place whether it be adding square footage, new construction, or 1031ing.

I read somewhere that it may be a good idea to buy large multifamily in a decent area (just don't really know what market is decent for this) or buy turnkey properties (I know of a couple reputable sellers that I can invest with).

With your large down payment they will still be mostly break even, but over time you'll benefit from the crazy appreciation that has been happening consistently in California for a century and the rents WILL eventually catch up. 

I’ve also considered a 203k loan for whichever asset class I’m able to get the numbers to work with, and over the year or two I live in it, I’d continue adding to my savings and building equity so I can use that to put down on another property afterwards.