Thirdly if tenant is approved by Homeowner association (they run criminal, credit, employment check) but I feel that tenant credit and employment history my be risky for me rent to this tenant, what would best way to reject tenant and not be on hook for RE agent fee?

The seller can reject, accept, or counter.

If they are looking at dozens of properties and only making low-ball offers that are rejected, it probably isn't the best use of your time.

That's why virtually every experienced landlord will tell you to have a specific set of criteria you are looking for in a tenant and have the discipline to reject anyone who doesn't. 

We made an offer at $65,000, which was rejected by the VA.

I'm assuming that you're going to reject this offer, even though it is a full market price for the house, simply because you can't afford the commission. 

In college I did door-to-door sales for two summers and learned a lot about persistence, dealing with rejection, and working with people.

As I said in above posts, it seems like they have been rejected by other landlords prior to viewing your property and are prepared with a "It's not me" answer. 

I would just make the offer today, and let the owner accept, reject or counter your offer.On the last property I got, the asking price was $125k & I offered $80k...The property sat for 2 months at the same price, & one day I got a call and the owner had accepted my offer...You won't know unless you ask, and if the seller rejects your offer, move on and let someone else overpay for the property...

I think my issue was I was running into architects who just, for whatever reason, were giving me large bids (or rejecting the project as too small).