I can't adequately express my gratitude. 

Two, buying on ROI, even if they have a decent house in a decent neighborhood, either they or their property management company cut corners and don't maintain the house properly and it starts to look "rental-ish" in a neighborhood with lots of owner-occupants.Three, they or their property management company fails to adequately screen tenants, resulting in a trashed property that the investor may not reinvest in to fix up to neighborhood standards, becoming a blot on the neighborhood.Four, the property management company may blatantly rip off the investor, pocketing the rent, the repair funds, and renting out the now crappy house to any derelict who can pay a few hundred dollars a month.Astute local investors don't usually make these mistakes. 

The problem is with the term "space heater", which makes people think of units which are specifically NOT designed or legal for primary heating source.I would have a heating expert familiar with these units inspect - if he is confident that they are adequate and appropriate, then proceed.

To me, aside from having a prior eviction on their record, lack of adequate income is the biggest indicator of future missed/late rent payments.However, I think you should take a chance and rent to them. 

I told myself in two years I would get started because I wanted to start with a house hack and being that I was just graduating college I didn’t have adequate income.

Really no further advice needs to be given or taken until that is adequately addressed.

With full cavity open cell insulation with no vapor control, it's entirely possible that the HVAC will be unable to provide adequate dry out.Troy does make a good point, which is to be careful not to cause additional problems with solutions.

That being said, WC comes into play for all employees as well as in the case of contractors without their own adequate insurance. 

Just because they are retired does not mean that they have adequate savings and investments to cover living expenses for the duration of their lifetimes.As I've posted elsewhere on BP, including just last night, I will go as low as 2.5 times under certain circumstances; see links:http://www.biggerpockets.com/forums/52/topics/73355-what-is-this-communitys-thoughts-on-cosigners?

The question then, is does the water drain away from the foundation/structure adequately?