All that to be said I don’t think either one is the wrong choice assuming your market doesn’t have capacity limits. 

You can never go wrong with white because it's a blank slate.

So my mom passed back in 2019 with no will and there was a lot wrong with the house at the time I decided not to keep it because I was pregnant and nobody would help me fix it up.

If you are worried about your buyer snaking your deal, then you got the wrong buyer. 

Part of me wants to buy now, but I could see that it would be really easy to buy in the wrong neighborhood.

I think you are looking at this in the wrong way- sure, there are lots of ways to finance properties without a conventional loan, but in most cases, a conventional loan is the best bet. 

If I was handed the keys today, I feel like I'd do a million things wrong.

Don't get me wrong my Broker is a fantastic person but she can't provide me what I need as a NEW agent.

As I understand it, with their name on the title, if we refinance in 5 years and remove them from the title, they would need to claim any capital gains on their taxes that year (correct me if I'm wrong, that's what I've gathered from CRA).

If you have to close on all 3 within 90 days, as it’s mentioned in your description, you’d have to close on 2 of the duplexes, then find a Buyer for both of them, and hope that nothing goes wrong in escrow, which means satisfying inspections for said Buyer, getting appraised on time, which is difficult right now and having zero issues with the title work, so they close on time… Then turn around and buy the third duplex prior to the original agreed upon 90-day deadline.