Another common problem is poor due diligence—jumping into deals without verifying the borrower or collateral often leads to future regrets.I’ve also seen over-leveraged borrowers cause trouble, prioritizing other creditors over private lenders.

There's a specific forum for House Hacking.You'll want to spend some time reading through there as it's a common topic.

Verify credit, employment, etc for you. 6) I would definitely want noise (quiet hours), guests, and treatment of common areas covered. 7) We've used Rent Manager as it focuses more on the financials which I think is super important.

@Mario MoralesI think this is a common question and the value that an agent will bring will vary by individual needs.

Quote from @Erick Pena: A "good" rental property is one that covers all expenses (mortgage, taxes, insurance, maintenance, property management fees, and any other costs) and still leave a surplus (commonly referred to as cash flow).Calculate cash flow as: Cash Flow = Rental Income − Operating Expenses − DebtThere's much more to it, but that's the basic idea.

It's expected and common for MTRs to have utilities included.

Are there any red flags or common mistakes investors should avoid when reaching out?

The common mistake here is that not ALL your equity is borrowable on a property and even more so on a investment property then an owner occupied property. 

After every negotiation, reflect on what went well and what could be improved.Negotiation isn’t about “winning” at the expense of the other party—it’s about finding common ground where both sides feel satisfied.

Learning from agents commonly working with investors is your next opportunity to find a mentor.To be honest, I wouldn't try to find a mentor from random investors on the internet.