I agree with @Joe Villeneuve that partnering would be the best bet for your first property, and in the same idea why I would suggest house hacking in your own area first.

Multifamily has gotten more competitive in many markets so properties have exchanged hands multiple times diminishing the margins.

Your best bet is to do the human thing by helping this person find another space, but also do the correct business decision which is to terminate this business relationship. 

Your best bet is to start with those articles and listen to some podcast episodes from BP.

I will do a 1031 exchange, I want to invest and distribute this capital into other property's. 

If I’m able to secure seller financing, what would be my best bet for financing rehab?

Now, if you're looking to close in 1 to 2 days, your best bet is private money or having a large enough line of credit (such as a HELOC).

Usually with HOA or other liens there is an option for the owner to make up the payments in default, plus legal fees, to cure the lien.One strategy would be to contact the owners with these liens (especially if they are a high amount,) and offer to pay the lien, in exchange getting the title ("subject to") and sell the property and split the equity.

I run my short-term rental business out of my personal house under my LLC, which I drew up a lease between that creates an agreement to pay for utilities, internet and common household products I need to function my business in exchange for the property.

Profit is profit, you pay tax on it.Your best bet is sit down with a cpa for half an hour or so, it will become much more clear.