Our dining facilities on base (which offer free meals to juniors/dirt cheap meals to seniors) are habitually becoming more and more empty with individuals choosing to spend money daily at burger king, subway etc. 

The ADU/DADU units still have to be 'junior' to the main house (smaller in terms of sf,   I think the size cap is ~1000sf) and there are rules around detached units as to their size and positioning on the lot.   

You need to find out if the "open mortgage" 1) was a junior mortgage to the one being foreclosed and 2) were they named and served?  

However, I was brought the thought of working with a compiler through one of our junior guys (who didn't understand it) and as it happens that we have a friend who does a lot of foreclosure purchases, it seemed like a good fit for him, even if it's a bit out of my normal realm.

Junior Salters at this pace would you sell anything or keep renting?

It's still risky, but not nearly as risky as bidding when a junior lien holder is the foreclosing party.

The most important thing you can know going to auction is, "Who is the foreclosing entity", meaning, are they the senior lien holder or a junior.

Junior liens like this often need to have a cash contribution from the buyer to get them to release as the 1st mtg holder usually doesn't offer them enough, usually 5-10%, to get them to release.

My theory (Based on very little knowledge) is that since the liens are paid based on priority we should either be able to negotiate with the junior lien holders or the court will allow the property to be sold to satisfy as much of the debt, in priority, as possible.  

It involves attending foreclosure auctions and identifying any properties that sell for a surplus over the mortgage, lien and junior liens.