I do pretty much like more SD than SA, but as you asked, the money that I have to invest it aint that much, goes between 30-40K to start and will be definitely for long term, as I said, I´m a beginner in this business in the US, as commons says I´m at the baby steps stage right now.

Providing a starter supply of items like laundry detergent, dryer sheets, and toiletries is common practice and works well for short stays.

if you believe this is a common outcome I have a bridge to sell you.  

Most commonly, laundromats are sold at a 3-5x multiple of SDE.

Common problem, no easy answer:(We try to allow our owner clients to arrange their own maintenance, but have learned the hard way there MUST be limitations:1) They can't hire our people!

Self-showing services are extremely common but that should be in the contract. 

I think it's probably less common here but I've often wondered about how difficult it would be to convert a detached garage, etc. on a property from a legal standpoint.

Beyond legal requirements, I’d love to hear about any practical advice for managing properties, finding good tenants, and avoiding common pitfalls.

Where I live mice are common as the cold weather drives them inside.

Everything you said is common knowledge.