A contractor company just getting started or a few years into the business might be cheaper initially but might also be out of business by the time you need a labor warranty issue fixed with the roof.If the roof was not installed properly even with the best materials than the parts warranty might be compromised or the claim denied all together.

I'm happy to compromise a little bit on price-to-rent if it might bet me some hope of appreciation, as opposed to investing only in cash-flow in an area without potential growth.

Thorough tenant screening, quarterly inspections, lots of documentation with photos at each step, figure out why they're angry while trying to compromise, and a prompt legal eviction when all else fails.

Now, in March I'm selling one of the houses (only 50% mine) and want to reinvest the money back into real-estate, specifically into a two/three-bedroom apartment and I have two options:a) buy one property with my own money and keep 100% of the cash flow (which I need); orb) ask the bank for two loans, buy two-properties and use part of the cash-flow to pay off the debt.I'm inclined to go for option b for obvious reasons, but I've never asked for a loan before, so I'm kind of nervous about the compromise.

That is always a mistake in investing.I would not approach any property so eager to have to compromise.  

I was originally looking for a multifamily for my first property, wanted to "house hack" and live free, but this was a bit of a compromise that worked for me and my girlfriend.

Most of the time are small compromises, but still annoyances.”

The seller however was concerned that we would not go through with the purchase, so as a compromise the closing attorney will hold the funds in an escrow.

The attached 2-car garage was left standing with a compromised firewall where the original house connected with it. 

Just keep moving forward and never compromise the quality of investments you're making.