I would keep detailed records of my deals to include photos that I could use later when I am approaching a potential funding partner.

Are you currently working on lining up funding or looking at potential properties yet? 

I can "cash flow" more from my stocks/index funds and high yield savings account with far less stress. 

However, I don’t yet have the funds for a down payment on another house, and I’m trying to figure out the best option for where to live while I rent the apartment.Do you have any recommendations for managing this transition or tips on finding a temporary place to stay?

I turn the tables on the wholesaler calls.. if i can get past the telemarketer and get to the owner I then explain to the owner how I can fund deals for them..

Since the properties are in New York you have a few extra steps you need to do to keep all of your funds out of NYs hands at closing.Here's an interesting BP thread on the South Carolina property tax issue you mentioned. https://www.biggerpockets.com/forums/725/topics/604427-south.... 

This money gets added onto the back of the loan kind of like a VA funding fee does. 

If you have cash on hand to fund the rehab and want to extract it soon after the project is done, you can use delayed financing.

I reached out to the individual marketing the deal to schedule a property viewing, but they’re asking for proof of funds (which I expected) and a signed purchase agreement or LOI.Is this normal?

You should setup multiple ways to accept payment.Our tenants have the following methods to remit rent (no cash) -1) Online payment sysem2) Zelle3) Bank deposit at Bank of America.4) Come to the office to remit funds.