For a problem that could have been resolved in a matter of hours/days or just a week at max, you can easily waste a few weeks here; - It is very often difficult to get them to act.

@Kiki Helland Detroit has been the most difficult city to find competent management.

It is a business, so run it like one, as @Tom S. said, start the process and follow through.Unfortunately you're in a Blue state so this will be more difficult for you, so yes get a lawyer if they don't respond immediately to your 'pay or quit' notice.Don't take any more partial payments, that will delay your case!

It is all dependent on the numbers.If you are planning on putting low money down, the odds of it cash flowing (or even breaking even) in the first year would be difficult. 

There are a lot of requirements towards the qualified opportunity zone of which you didn't mention the three most difficult parts1) The funding of a qualified opportunity zone needs to be through capital gains.2) There has to be an entity structure of which there is more than 1 owner3) You have to materially rehab the propertyTalk to an accountant to make sure you have all the requirements met.

In your networking/loan terms search I'd reframe your ask, because what you are asking for sounds MORE risky and therefore difficult than another request.

She eventually got arrested and sent to jail right after I kicked her out so suing her for add'l damages above the security deposit amount would be easy to get the judgement but difficult to get paid back.

Deciding if it was a borrower's homestead could be difficult.  

One visionary comes up with the idea and creates an ingenious product, but later generations will always have the advantage of hindsight and trial-studies from which they can improve their design.It's very difficult to say where the whole space will go. 

Coops can be difficult and I understand what you mean when you talk about the appreciation, as I bought a condo in Mott Haven and appreciation has been slower than I hoped (thanks Covid).