I do have to disclose that I am on a student-based work visa at the moment called F1, I am unsure whether this will affect my ability to buy real estate so would love more guidance on that!

I'm thinking of starting with buying/rehabbing my first house being cash, then refinancing after I rent it and repeating.

Cash-out refi costs money to originate the new loan, appraisal fees and your PITI will increase affecting cashflow. 

Yes, the BRRRR (Buy, Rehab, Rent, Refinance, Repeat) strategy is still alive in Philadelphia, though some aspects have become more challenging in recent years due to shifts in market dynamics.If you’re considering BRRRR in Philadelphia, areas with recent or upcoming developments, like parts of West Philadelphia, Brewerytown, and sections of Northeast Philadelphia, can still present good opportunities, but base everything on section 8 rents to see if the DSCR and LTV makes sense

This will add about $600 in potential cashflow to unit #1 but has an overall negative cashflow affect of $1000/month from a 4-unit as existing.2.)

Wash, rinse, repeat.

Hey Kevin, when it comes to flipping houses does a bear market or high inflation period have a different affect, or is it still a safe investment?

After that I will use my savings to fund the next property and repeat the process.

If you haven’t done so, join AZREIA or smaller local meetups, where you may meet investors (who ought to be repeat buyers).  

Those crimes are serious felonies repeated over and over again.