Can I get fairly accurate information from them (about how much they will approve me for, how much they would require down, interest ect.), without having to take credit hits?

I heard that it will be nearly impossible to get traditional financing with an LLC, is this accurate?

Doing this your numbers will be more accurate and you don't have chance of the seller skewing them.

While this information may even be accurate, until a probate judge ratifies that person’s authority to take action on behalf of the estate, the property manager is unable to deal with that person legally.

I would probably reach out to a local property manager in the area as well for some more accurate ground truth as well.  

Do the NADA guides give accurate values?   

Have you found it to be an accurate indicator of whether an area is sketchy or not?

Don't count on another person's numbers or estimates or whatever being accurate.

I just partnered up with a general contractor who's going to come with me when view properties to give me an accurate estimate on repair costs.

In order to get an accurate ROI you should include these things.