You don't need an ITIN to purchase, but will need one prior to next tax filing season with IRS.  5.

Facts below:-3.5 month close to season downpayment fund source i will be using-$500 earnest money deposit-Current Valuation: $180,000-Sale Price: $170,000-Tentants in place, rented at $1290/mo-historical 1% vacancy

So you can grab all the culled wood (70% off) before the other mutts grab it!!!

4 years in, all is fine - knock on wood..... 

My interest quickly grew beyond the short-term rental world as I listened to seasoned investors' testimonies of success at BRRRR-ing, flipping, wholesaling, and more.

(I have been reading books, cleaning up spreadsheets and preparing for tax season, enjoying my family) Is there more I could be doing?

Lots of investors use cash-out refinances as part of the BRRR strategy to pull money out after rehabbing and increasing the ARV, but generally need to wait a 6 month seasoning period if the capital they used up front was borrowed somehow (hard money, private money).

Try a different lender and the first question you want to ask is about their "seasoning" period. 

After I purchase another property and the opportunity presents itself, Is there any loop holes if I need to purchase another property before the seasoning period is up?

This "mindset" is what is putting newer investors in peril right now and over-leveraged, seasoned investors who wanted more doors to boost their ego.Long-time investors are cash full and responsible with their portfolios and are going to ethically navigate this time and buy the best deals.