I enjoy real estate so I am thinking about selling a couple properties and using the proceeds to start 1) a small private money lending business; 2) patiently shopping for commercial properties and flipping them; and 3) getting into land and commercial spec development.

If you're patient and humble and only buying good deals in decent areas, you should be fine.

I tried to find freedom but what really happened was, I have never worked and endured and been patient at something this much this long.

There are plenty of qualified tenants out there, be patient and wait for one that meets your criteria. 

Wealth tends to favor the patient.

For example, if it's a maintenance issue and it hasn't been done or done to their satisfaction, I instruct them to send a certified letter and if it's not resolved within 3 days of the date of the letter, then they can hire their own maintenance tech and invoice me or the property manager for the expense.

You simply need to be patient and don't rush into a deal.

Someone who buys a property with probate title problems and a non co-operative heir, is either a gambler or a very patient buyer who wants the property badly enough to put up with the hassle or doesn't understand the problem.

@Dan Deng, You can afford to be patient for a while. 

It does take time to find a good deal though so just be patient.