I have gone after sellers multiple times for concealing problems.

And I carry concealed, so they wouldn't know. 

This WILL come up and they do have a right to ask about it when you sign documents giving them permission to ask about it, and that's exactly the type of stuff you'll be agreeing to in a loan application package.Another piece of advice, don't conceal facts that could be deemed material in nature and always be honest when engaging in a large transaction like a mortgage. 

The person could have concealed that from you and smoked inside anyways, so at least they started by being honest, which we find to be a good indicator that they should be in the future. 

There may be another way of doing it and if I end up using a 1031 exchange in the future I will for sure attempt to conceal that information until later in the transaction simply for some more negotiating power.

It's a risk many are, and have been willing to take.I've read some people talk about using a Land Trust to conceal the fact that ownership interest has been transferred, though Title companies do not like it.

(investment property)As long as it is not concealed, transferring the property without lender permission is not illegal or immoral.

It does help conceal identity to the tenants if they are not paying direct to you and you utilize a property management company.

There is even possible evidence of concealing the blackened copper on the AC evap coils.

Didn't think so.Here's a good rule of thumb: If your deal can only make sense by concealing facts and piggy-backing on the seller's current bank financing terms, then it's not a "deal."