A reserve is unnecessary, but I still keep around $15,000 - $20,000 in my account.The point is, you should sit down and assess your personal finances to determine what the worst-case scenario may look like, how much you would need to cover it without impacting your life, and whether you will need to build a reserve.

Another possible option is actually selling the property to our son at market price, but even if we do that without a realtor, I'm thinking that would probably incur unnecessary costs.

and then we would end up doing major renovations a lot sooner than we would have had to otherwise and would have to absorb unnecessary costs to our business because we didn't charge adequately or at all every tenant who were leaving their own damages behind after them moving out.

Many Boards strive to keep the monthly fees low, but in doing so they are simply deferring maintenance and cutting other corners, which leads to unnecessary damage and more costs that will eventually require a Special Assessment or significant increase in the monthly fees.

They will absolutely eat you up with their unnecessary fees.

Dig up and dispose any unnecessary bushes.

I've experienced more than six figures of incremental, unnecessary out of pocket costs related to contractor negligence (and fraud) to the point where it has influenced my strategy and how I am willing to participate in REI.

They are both forms of cost that are unnecessary. 

If not, then you can improve your savings rate by managing your spend rate; try cutting unnecessary expenses, and creating and following a budget.

I am going to go ahead with the advice from this forum and do networking and build those connections and trust with other investors.Since at the end you are considering go in all this for 10-20% profit per property did you consider investing abroad since you don't have experience and there are companies or agents in Europe that can do whole cycle with you and give you same kind of profit with no expertise needed from your side and no unnecessary pressure.