Real Estate Referral and Management Fees

I am a Canadian realtor with clients who invest in US real esate and in need of some basic advice.

1. I get paid referral fees from the reators in the US through my brokerage network. Do I need to report these to the IRS ? I do not work in the US and do not have a green card or VISA.

2. I have a Canadian management company and just also incorparated a C corporation. Is it legal for the Canadian company to manage property in the US or does it need to be done through the US Corporation. The functions relating to the day to day management of the property are performed by local US contractors.

3. If I get paid consulting fees in Canada in respect of rpoperty situate in the US do I have to declare tax to the IRS on those fees ?

Thank you in advance.