I finished by telling them that if I got one more complaint from either of them about this and it wasn't legitimate that I was going to blindly deny renewing both of their leases when it came to pass.

I am wary of being in a blind leading the blind situation.

As a landlord, I would prefer not to lose an A+ tenant due to blind rent raises if I can legally implement such a strategy.

Seems like even with the best Due Diligence, I would have been going in blind.

At this stage, you can do a blind offer, or you can make the seller and the listing agent happy and actually go SEE the homes to refine your numbers. 

And finally, are they obligated to disclose any back dues to 3rd parties or are we to bid on the blind.  

Our property managers have been attacked, my dad was shot in a drive by (he lived but went blind), and it's basically impossible to get rent money on time, even from Section 8.

Not to sound disrespectful but even a blind squirrel will occasional find a nut.I ought to know because I've been both the squirrel and the nut.There is no perfect system, campaign or single message that leads to profits. 

Any pointers - I have blind spots and likely do not even know all the questions to ask.

First purchase and am excited to get started but also not wanting to jump in blind!