Dont know where to start any suggestions will be great thank you For the 300k property they are probably not going to let you pull any money out based on the amount of credit you already owe.

If I were to pad the trustworthy broker's suggested ARV by 10%, and the trustworthy contractor's quote by 20%, would you say that I would likely be within realistic range, on average? 

Paid a top local esigner to come have a look and all she did was insult our cute little place that was doing just fine.....But I think where a designer could add value is by suggesting unique areas, like game rooms, coffee bars, outdoor BBQ/play areas, and stuff like that. 

I suggest consulting with a real estate attorney to ensure proper structuring of the LLC/land trust and review the tax and insurance implications.

The fact that RentRedi doesn't have another option (and apparently aren't open to suggestions?)

I would suggest you go the commercial route. 

As Jay suggested, you should pay for two hours of a good attorney from your state, who is well versed in foreclosure law, and ask them to walk you through and explain you the entire process. 

If you have specific questions or specific goals, I'm sure the Bigger Pockets Community would have suggestions for you.

My lawyer suggests in a situation like this that I give them a notice that I am the new owner and that as of a certain date they owe market rent of $X,XXX.

Is there a alternate way to structure it, please suggest.