I have at least one lender and one agent, but would like to fortify those positions with other reliable sources as well to round out the Core 4.

It's likely to be abused and a source of conflict between your three renters.

Friends, family, private sources, banks. 

(More income gets taxes and at a higher rate) Just because your tax went up doesn't mean your CPA did anything wrong.As a CPA myself, my least favorite part of the job it going through the details of showing people why thier taxes are going up and are going to keep going up but I always do it.

Which makes it the best source of creating lists based on filters.   

For your financing needs now, I know of no sources but maybe someone else on here does. 

Would you help with sourcing contractors as well as critiquing their work?

Favorite amongst tenants.

If accomplished, enhancing the latter would be great.Much of what I have learned so far has come from American sources like 'The Book on Rental Property Investing' by Brandon Turner, 'Rich Dad Poor Dad' by Robert Kiyosaki, Real estate books written by Ken McElroy, and of course the Bigger Pockets podcasts. 

Once we have a tenant she plans to refinance, use the lease(75%ish) as another source of income and co-sign on my first property!