My 2 cents.
It isn't really relevant what NOC was mentioned in your employment letter.
It's your responsibility to indicate a correct NOC that is aligned with its lead statement and duties.
1. Common law, dependent children. You don't need to include your ex wife. What do you mean by their dependent children?
2. Yup, it's okay.
3. Your common law will be disclosed and included as accompanying?
2 weeks stay is quite a long time, you should have pretty much enough money.
The fact that you will be staying at your brother's place doesn't reduce a funds requirement.
From what I see you have more ties in Canada which might be an issue.
You are not required to submit them at all, they are just nice to have.
A reference letter which states how much you were paid is a strict requirement.
But there's a lot of discretion here. There might be more leniency in your case. So no harm in trying to apply earlier not meeting all the requirements.
Who qualifies
With certain exceptions, to qualify for OHIP, you must meet all of the minimum qualifications listed below plus at least 1 of the additional requirements.
To meet the minimum qualifications you must:
be physically in Ontario for 153 days in any 12‑month period
be physically in...
It depends on a decision maker. Most often you get an update and/or a decision on your reconsideration request. Sometimes IRCC just reopens your application and makes a decision again. Not always a positive one.