I guess 401k's the only benefit of a 401k is it's tax benefit and I'm making an instant 100% ROI with the match... but the issue I have is that my money is tied up for the next 40ish years (I'm 28). 

Pay off the HELOC and use the remaining cash for first property?

New buildings may requires those improvements, and rehabbing may require installation but otherwise older buildings can remain as is.

In my state, the law says they remain responsible for the terms of the Agreement until a replacement tenant is found and that I must make a "good faith effort" to find a replacement renter.

The rule in lending is you will always get a lower rate and a higher LTV loan to value on your primary home.So if you tie up money in a smaller investment and then need cash your limited by two factors the loan size and the Non-owner occupancy if it s a rental you get a lower LTV.

Get some nice ones that tie your theme together.

Use the remaining cash and cash flow to buy more rental properties and potentially other 'rent to down payment' properties.

Differing costs.[4] The owner cares most about SPEED of repair because they want to re-rent as fast as possible.[5] Some of these products are made for rental use and are faster to repair.[6] Repair cost includes labor and a possible up charge by a local management company for handling the repair.[7] LVP likes to remain in a certain temperature zone, if you do not use A/C some types of it may buckle.[8] At least they didn't charge you pet rent for the rodents (that is a joke).If they replace it, just be as careful as you can.

How is that remaining 15k typically disbursed? 

Purchase price: $515,000 Cash invested: $138,263 This is a 6 unit MF with all one bedroom apartments we bought and looking to add value by exterior cosmetic updates, increase monthly rents towards market rates, and renovate the remaining 4 units yet to be updated during turnovers.