I am someone who invest with more regards to good leaders at the helm rather then “all current or outstanding situations” as long as him or her and maybe self to a degree, can understand where the company is heading, how and why it’s aiming towards that point.

Outstanding balance roughly 32k lower than when loan was originated.

Coming to the point the lease is coming to end next week and they have outstanding balance of over $3k including late fees (I know should have given the eviction notice the first month itself.. lesson learned)They expect me to just withheld $500 from security deposit, so they can pay other bills and they will continue paying a small amount every month (so they say). 

I'm encouraging seller-financed noteholders to consider small partials as a way to raise cash. 12 - 24 months on 60+ outstanding payments will result in a minimal discount because, in the most common partial scenario, the buyer is buying near term payments and taking less equity risk.

. $60k for a 15 unit mobile home park equates to $4k/unit, which is outstanding!

Those commercial tenants that have expressed concerns over rent & cam payments, I've been using an addendum "security deposit towards outstanding balances", where that security deposit will need to be replenished at least 6 months before their lease expiration.

Would it be possible for me to take a loan out for 100k to pay off the outstanding loan and then seller finance?

How much capex has been spent in the past and how much deferred maintenance is still outstanding? 

Because we do value adds extracting much of our initial investment, we have achieved outstanding RE returns.  

Just be careful not to take a steep discount on your current house and then pay close to top dollar for your next place.Regarding your HELOC, as others have already stated, your outstanding balance would just be settled with the sale proceeds at closing.