I've tried a lot of sources craigslist , door knocking , mailings , etc 4. monthly advertising form multiple sources would be around $400 total per month 

Doors don't cost that much.

The detached garage and windows could use some work which could add value presale.

Doesn't sound like its worth paying for an eviction and not worth the animosity over beating down their door over $100 bucks and then maybe trash your place. 

Some work I would need done would be some tile replacement in a bathroom shower, a leaky sink faucet replaced, and kitchen fan replaced / fixed, and possibly (I am undecided here, depends on how much the previously-listed runs for cost) some framing done - My property was originally built as a single-family home and split into a duplex, but shutting off / sealing off a door, which is still a door.

Our goals are to do what it takes to eventually end up with 50 plus doors in well maintained, well managed, and well-financed buildings.

So I've been working with my Real Estate Agent (Also an Investor 10+ Years / 12+ Doors) and we chatted on the phone.He asked, what is my Plan/Goals going into Real Estate do I have them written down, what do I want to accomplish this year?

You should always know your exit strategy before walking in the front door-pun intended!

Is my only option door knocking or direct mail?

However, the interesting thing is the house next door, which is a single family, sold for 365k.