If they don't show I would have been there anyway doing work so I'm not at a loss. 

So I'm at a loss for how much I should estimate the repair to cost/ how much I should discount my offer by.Thanks in advance for the help 

, or just taking some of their investment off the table (risk reduction), generating a partial taxable event to be used again operating loss carry forwards, etc. 

Get a $5k deductible and protect yourself against total loss.  

This loss is expected and not a problem.

One month of vacancy would cause a negative cash flow that would take far too long to recover from.

Investors buying 5% cap rate properties are most likely banking on rental increases while taking appreciation losses on their taxes as well as mortgage interest.  

Both my properties are cash flowing around $200 per month but as I mentioned I have only had them for a few months (will have them about 12 months by the time I am ready to purchase my next) and I am not sure if lenders would recognize that as income or actually count the mortgage payments as a loss in the debt column.Any advice or insight on this would be greatly appreciated. 

M2M because if tenants break the lease you need to actually prove that you did your best efforts to find another tenant before you can actually try to recover anything due to lease breakage. 

If you fail, you are young enough to recover.