Treat them with respect because you might be introduced by them to another property owner that wants to sell, an investor, or another buyer that can share with you some unusual information.  

Fees for garbage pickup may be included in the owners property taxes; thus, you may be paying for this.In addition, one reason the current landlord may be paying the water/sewer charges on this duplex is that there may be only one meter for both sides (not unusual) and it may be cost prohibitive to run a second meter.   

It would be unusual for tenants in GNV in a triplex or quad plex to not pay utilities.  

You have a higher CAP rate on a cash purchase than cash on cash on a financed purchase which would be highly unusual.

So in that sense, I see a balance I can strike, while at the same time, expanding in uncertain futures.

While unusual, mortgagees might deny permission to rent out their homes except in emergancys.

The fix n flips financing is usually just 12-13 months so at some point soon you'd need to pay those bridge lenders off.I am uncertain how I feel about 401k/HELOC - Personally, I'd hate to risk everything in an effort to grow faster.  

Along with a delay prior to closing....Uncertain how to relay my credentials, nor a contact without drawing the forum police.

But either scenario is uncertain and has risks.

It's also not unusual for flippers doing deals in volume to use Gap Lenders and giving those lenders sizable returns for their risky investment.