.- Contacting to the seller directly is un-ethical, this is not because you are by-passing the agent but because the seller is not a real estate professional, and he might disclouse things that affects him on the deal that will make the negotiation tougher for the seller, in which case it will be a lose-lose situation for him.- You should look at talking with a real estate attorney if you want to know more.

Now if they broke down the invoice by line item and showed the break pads cost them $25 and they are charging you $170 in labor for the 1 hour of work how does it make you feel? 

Maybe try visiting and showing your face so you're not just a random OOS investor if you feel they're taking advantage of that.

From what I've learned so far, flips are generally considered one of the better investments in this type of market (please feel free to correct me if my understanding is wrong!).

Single bath houses are both harder to rent and sell then 2 bath houses Did you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?

If you feel they're being too harsh, think about their intent.

If you have any more questions or need further assistance, feel free to ask!

We are approaching the capital to buy a cheap cabin in cash if we wanted to, but feel like that isn't the best use of our nest egg. 

You answered your question in the last sentence - disclosures are required on conventional but not for DSCR - these are really aimed at overprotecting the consumer (non sophisticated or non real estate professional) - since DSCR Loans are 100% business purpose and for investors (and typically for experienced investors or non-first time buyers only), there is less need to overly disclose / overly explain everything in a disclosure since its assumed they are experienced and know the basics

I have to do a little more due diligence before I feel comfortable with sending them any of my personal info.