As you learn go to meet ups, try to network/glean from experienced people and listen to podcasts/videos. 

My plan was to "self-perform" a land contract by filling out a purchase and sales agreement for a land contract that specifies I will take over the mortgage payments, get authorized on their mortgage, and be authorized essentially to fix up the property and eventually sell it on the MLS since the land contract will give me that control/equitable interest.

Possibly should have done something about the deposit but everything that happened with him moving out was essentially conducted without notice to me and it's hard to say now whether I even found out he wasn't there within 30 days of his actually moving out.4.

We also can't have renters dealing with the humidifiers as it is a mold problem/foundation issue if it isn't taken care of.We are taking pictures and videos of everything, we have multiple professionals that have documented everything (and told us to lawyer up) and have neighbors that we have already had agree to discuss their  drainage problems when we get a lawyer.

They handle:Monthly Payment ProcessingEscrow for Taxes and Insurance: They ensure property taxes and insurance are paid, which is essential to protect your interest in the property.Record Keeping: They also maintain records, which can be invaluable if any issues arise during the term of the loan.ConclusionGiven the details of your property and the $200,000 sales price, a possible scenario could look like this:Down Payment: 10% ($20,000)Loan Amount: $180,000Interest Rate: 8%Amortization: 30 yearsMonthly Payment: Approximately $1,320 (principal and interest)Balloon Payment: Due in 5 or 7 years (this allows for refinancing or payoff while giving you some flexibility).These terms are flexible and can be adjusted based on the buyer’s credit, down payment size, and negotiation.

Video tours of the properties help this.

If this is the case I run the risk of becoming underwater on the mortgage and getting myself essentially stuck in a property I don't want to be in long term.

And the ones that affiliate videos seem to be a commercial for BL, not tutorials. 

If the separating wall is a load bearing fire wall, it would have 2 sets of framing material on either side, essentially you have 2 completly independent houses joined by the roof, you can go in the attic and see if you see sheetrock going to the ridge of the roof. 

I also do a YouTube walk-through video of everything a guest may ask and go through everything at the property.