Renting out a room in my primary?

I recently purchased a condo that I plan to live in for two years while I do some basic upgrades to it. Both bedrooms are ensuites, & my long-time friend is planning to sell their home & rent my second bedroom to give them working capital for us to do some real estate deals together.

I'm thinking it would be advantageous to have them pay me a set amount that's over 50% of the costs so that it can be considered income. (I work in the non-profit world & am not looking to make a change, which is why I would like to show additional income.)

And technically, they would be paying over 50%, but we would even it out on the back end like groceries, etc., but if we go this route, we would stick to the terms to be able to show/prove that they pay more than 50% of shared mortgage/household bills.

Some questions I have are:

They would be signing a lease (& a two year lease would be fine with us if it helps), so at what point can this be counted as income?

What percentage of their rent would be counted as income?

I know I would then qualify for some various write-offs, but wouldn't this go against the income I'm trying to show?

They make a good bit more than I do, so it won't really be a deterrent for them to have an increased rent payment, but am I overlooking anything?

Any other advantages &/or disadvantages that I'm missing?

And I definitely get that people may want to warn me about living with & doing business with friends, etc., but we've worked together well in the past, & we own investment land together, & we've never had an issue, so we're wanting to grow faster, & this definitely seems feasible to us.

Thanks in advance for any insights!