There are so many variables in any situation that it just isn't possible to be specific.  

I'm not a fan of sub2 wraps, as suggested in Podcast 70, because it's just too many players and too many variables for my taste.  

Actually, there's so many factors and pricing can have so many variables that pricing a home right is a valuable skill in an agent. 

On the HELOC we are getting a 9% variable rate with 5yr term but the appraisal came back low.

Just by reading the adjustable rate rider they'd have know this.All things being equal you should be fine with an ARM but all verify all other variables are the same

Cash always flows in all Real Estate investments, the variable is which direction that cash flows

Other variables such as cashflow positive, value add opportunity, equity on the buy, and multiple exit strategies help can either make sense during the hold period or work themselves out. 

I would also add a variable-speed 3/8-inch cordless drill-driver. 

There are also variable tax additions for voter approved projects/charges. 

I think that because I'm an independent contractor affiliated with a very successful company and I have a set schedule, a lender should be able to see that there isn't a ton of variability in my income or a risk of losing it.