Very low, a refinance would force you to give that up and because it is your primary residence and you presumably plan on living there for a long time it probably isn't the greatest idea to blow that up. 

It's anti-diversification but at least it's (presumably) a devil you know...at least more so than KC and St.

You presumably get a better deal because you have "insider information" in the form of a property owner that has told you (and only you) that they want to sell.

I presume he is going to be renting it out.I can tell the MLS folks to let me negotiate directly with said broker or negotiate on my behalf (for a nominal fee).If I choose to negotiate directly with the broker on this offer, is there any legal or other precedent that prevents us from suggesting in the negotiation that we let his "official" offer expire (he put a 48 hour clock on it) and we take the deal offline and accept it as is to eliminate the commission where we both are happy campers in the end?

Presumably the only downside would be some minor annual fee for maintaining the HELOC, but that's likely pennies compared to what you're talking elsewhere for an investment.  

The owners of record do technically still own it and can sell/rent/strip it until the bank forecloses, and (as I understand it) they can legally they can deed it to you without affecting the BK, but then you have a house with all that debt that presumably needs work. 

Why not just be upfront/honest about your fee and explain the benefits you are presumably providing? 

The only obligation you have to offset is the taxes and insurance which presumably is covered with with 75% of gross rents.  

Virtually every commercial appraiser would impute costs for property management if a property were presumably self-managed.

Ethics aside, let me get this straight:Day 1: You walk away from a contract the agent wrote up because you don't think the agent earned the 6%.Day 2 (as you stated, "next day"): Agent puts property on the market, presumably putting in very very very little additional effort because it is the next day after all and you say he wants highest and best the "same day."