As @Christopher Phillips writes, showing before receiving applications is the normal process.I suggest giving your potential applicants specific criteria they must meet for consideration: income requirements, credit report, eviction/criminal history, pets/no pets, and so on.

I was wanting to use that 18k towards an investment property i am seeking to acquire..any input or suggestion if this is even feasible and if it is the easiest way to go about it...what  custodial companies would you recommend..thank you for time and consideration in hearing out my question

and do I even need to take into consideration the vacancy rate if I am reselling?

As this is a common area, your landlord needs to take other tenants into consideration.

However, a leaking roof has caused considerable water damage to the floors and walls inside of the house.

However, a leaking roof has caused considerable water damage to the floors and walls inside of the house.

A lot of those things takes in consideration on if it’s worth the money, time and energy.

Since those listings are expired, the sellers might be motivated to just sell them on a rent to own vs. have the house sit unsold, vacant and them having to make another mortgage payment.Oh and the rent to own tenant should also pay a non refundable option consideration - (like a downpayment) so that he will have the right to buy the house (and the seller can't sell the house from under him).

One thing to take into consideration is that the VA requires you to have landlord experience if you buy a 2-4 unit property. 

Will definitely take it all into consideration.