I have excellent credit (745) and can provide w2 and all the required documentation.

My question is, are the rates/terms substantially better if I were to look at the local community banks/credit unions?  

I think it was only line of credit like a mortgageHELOC = home equity LOC, which means securedby your home as a primary residence.Mortgage or othe type of loans can be done on investments, but I'm not a lender.Ask @Chris Mason 

How is your personal credit?

Lots of opportunities but all with varying price points.

I have good credit 800 and a great w2 job with 2 other investment properties (in a different state).Should I just accept the 25% down, or will a conventional bank even offer a 15% down?

Unless vets are considered to be so special that credit scores do not matter a 500 score will be no where good enough for any conventional bank loans.I would rent, with luck you may find a mom and pop landlord that does not care, then work to repair your score over the next couple of years.  

My credit card only charges my Netflix and is paid off in full to maintain 3 lines of credit.

Do you just tell the tenant that you have a space they can live on the cheap, no credit check, no background check, LL can raise rent whenever he/she wants, and you need to leave with 30day notice?

They say, " if you can't take the heat then stay away from the fire", in other words if you can't absorb the cost of doing business then you are in the wrong business, simple as that.This is why I can't stand all of the jerks selling people on the concept that people can do real estate with absolutely no money, no credit, and no experience.