Items like a missing doorbell or blinds may fall into wear-and-tear depending on their age.

I ASSUME you’re talking $400+ in extra expenses for providing water, power, sewer, gas, internet, communal area cleaning, and exterior maintenance.

I don't know that any of this would affect a new appraisal, but there may be some comments by the appraiser, which may or may not hurt you depending on why you want the appraisal in the first place. 

Ultimately though, it will depend on the lender and the availability of funds (assistance) available for the demographic area that you are purchasing in.Do you have a property that you are looking at?

The amount depends on negotiations between you and the property owner. 

The structure will depend on the down payment, quality of borrower, terms of note, your cash out of the note sale needs, and other factors. 

You want to focus on markets that work with your plan and also where you have a personal connection with someone, even if you build that on the internet.

This will vary depending on if a handyman can do the job or a licensed contractor is needed.

The question is mostly a personal financial planning question and it depends on your preference and what balance of risk and access you'd like and would be comfortable with.

I have used this as well for tenants who don't use the internet and/or don't have a checking account of their own.Otherwise, yes, you could do the PO Box.