They don't need to know the details regarding mortgage price or other financial details but they will be seeing you around the property.

Should I discuss some bullet points and do a small contract between me and the buyer or is there a standard contract for such that we can agree up on terms prior to handing the deposit to the title company?

Many of them make big promises, then provide very little actionable advice.Second, what you are hearing about is referred to as "arbitrage" where you rent a property as a long-term rental for a set price, then you furnish it and try to rent it on AirBnB for a profit.

My partner and I are eager to embark on our first real estate venture by acquiring a long-term rental apartment in downtown Chicago.

If they are good, they should be absolutely definitive on rate, terms, costs, etc.

Now, I have a portfolio of Short Term Rentals and Long Term Rentals.

Most people just use the term but there is association management, apartment/ Multi-family management and then property management.For instance, in Florida, you need a license to practice Association Management (in most cases) and a real estate license to practice property management (in most cases). 

Can anyone point me towards a private money lender offering these terms ? 

However, in practice, the broker always negotiates for the seller to pay this commission.Negotiation Tactics: Good brokers negotiate to ensure that the buyer is not out of pocket for their agent’s commission, aligning with common practices and making the process easier for the buyer.How to navigate this:Ask for Clarification: If you’re unsure or need reassurance, ask your broker to explain how the commission will be handled in your specific transaction.Review Agreements: Carefully review the buyer’s brokerage agreement and the purchase agreement to ensure that the commission details are clear and that the seller is covering the buyer’s agent commission as negotiated.

Not buying/selling for others like an agent would do.Think more like get a rental or two or a short term rental to get those hours.