You have to read the entire Article in its entirety, all sections together.The short answer is, "the action" refers to the action a purchaser is entitled to bring for possession, provided it has given notice and waited at least 6 months after the issuance of the tax certificate. 

B) The pros and cons of having two properties instead of one (especially in terms of liquidity).

I will send you a DM with a recent podcast episode we did on areas that are upcoming in 2024If you want, I put together 20 years of a mind dump into a short article that breaks down the Chicago suburbs and where I think are the best opportunities and more importantly to stay away from. 

A HELOC should be used for short term cash needs. 

I calculated a $4800 monthly payment on a 15 year term after 10% down.

You seem pumped up to do this, but do it first at a local meetup (in terms of connecting with people) or else you are just going to get a bunch of people trying to sell you services or on how good they are.

I would recommend that in the short term you include that comparison against any real estate investment you  consider.  

Essentially she wanted something in place in case something happens to her in the short term.

Can someone share insight on a standard or common structure for loan terms when you are a private lender?

I don’t plan on living in Philadelphia long-term but probably will for at least the next year.