before you go any further. check with a professional, ie engineer,to see if roof will support extra weight. roof structure is normally designed for dead loads, not that much live load

For the past few days I've been weighting out the pros and cons of two properties.

As for trying to negotiate large concessions, and in this case a 30k price reduction, you can try to address your concerns with the seller, but more likely then not they have other offers waiting on the table.

For the past few days I've been weighting out the pros and cons of two properties.

Lot's of factors that only you will be able to weight out.   

If so, I would probably discuss with her your limited options and, if you need to, offer her a small reduction in rent.

I'd need $60k reduction on price and 3% interest rate to MAYBE pass with 3.5% down.

Maybe extend the shower to 4x6 tiled with a seat on the Water Closet side.It might make construction cheaper by getting rid of the storage area cubby spaces (less complicated walls and drywall), and open up the shower for use by older, or larger, or over weight people.Also moving the stove to the center of the serving bar might allow for more convenient cooking, as things could be set on both sides of the stove, then swap spaces with the sink and dish washer.

If one genuinely plans to hold the loan without selling or refinancing for the full term, then rate should carry more weight, but even then, a few extra payments to principal easily offset a higher rate.I've had at least 5 investors this past few weeks show me offers for 4.5-5% rates on some of the worst loan terms I've ever seen.  

I said no problem, you pay me a portion of that rent every month you are unable to uphold the agreement, and no rush, we can do this forever. 3 months later we were able to close with a price reduction of that rent.If I was purchasing your property as investment income, and the seller is delinquent, I would notify everyone involved that I will be taking action.