I've read many times that it's simply included in the LOI terms and clearly established/negotiated with listing agents whenever present... but what if the LOI isn't legally binding?

If the house is in bad shape you should identify how much of an investment for renovation it will probably need (include some hourly rate for your work into it even if that is not actually paid and include work estimates for anything you can't do yourself).

My advice to investors, especially rookies, is to keep everyone honest (including oneself!) 

Block the chimney, make sure it is non functional, and include that in the lease.

The cash invested includes my original down payment and an estimation of what the building and furnishing costs have been for the ADU.

That is by definition of a dwelling unit from Article XII in the Land Development Code which I have included below.Dwelling Unit: A room or groups of rooms forming a single independent habitable unit that is used for, intended to be used for, or may be used for, living, sleeping, sanitation, cooking, and eating purposes by one family only; for owner occupancy or for rental, lease, or other occupancy on a weekly or longer basis.A dwelling unit shall contain an individual kitchen, as defined herein, sanitary and sleeping facilities.

You should always be able to get a straight answer - but its going to depend on the loan product type - conventional with hard hard and set rules, Non-QM/DSCR these are likely going to differentiate in some ways (including this area) among lenders, so it can be different by lender.Some DSCR Lenders for example are OK with Short Term Rentals which obviously wont have a lease (but may require other documentation like a listing or history). 

Including parameters around the care and usuage of additional kitchen appliances or smart technology around safety could be helpful.

I had one tenant who bred pitbulls in a neighborhood where i own 16 units on the block. 5 of me tenants plus my handy man had purchased a dog from them and out of all 5 that moved out including the breeder every single property had damage to moldings doors and walls from dog scratches.

Now I'm slowing getting all my tax docs ready for my CPA but I'm confused on how bookings in Dec 2023 affect my 2023 taxes.So for the bookings that happened at the end of last year Dec 2023 but didn't get paid out until Jan 2024, do I include these bookings/income for the 2023 tax year?