I've seen some differing view on if this is legal or at minimum troublesome so would need to consult an attorney when/if we get to that point.I'm thinking on $500k home 3% Option, 2 year lease option at today's market price + say 2% annual appreciation, so $520,000. 

Otherwise I can always consult the Land Register for my province but each search costs 1$, which can add up quickly.

I currently work as a Sales Consultant for one of the biggest builders in the Nation.

If you are able to build a list you can JV/Partner/Consult with people who have vacant homes or places that need filled and make a small fee.

Or do we need to find separate engineers / consultants for each item? 

Always consult with your attorney before you rely on the above information.

So just one accountant would do the job, just get some free consultations before choosing one to build a relationship with. 

Always consult with your attorney before you rely on the above information.

If you are dealing in retail or larger commercial projects, a NY attorney should be able to help you as long as they have what we call a "local counsel" consultant or a member of their firm with some knowledge in that State, which most commercial lawyers do.

Also, to be safe, you should consult with an attorney familiar with RE laws to make sure you do your deals legally and that your protected.