Dear jondur.
NROs enforce written laws and in the case of Métis harvesting rights there are two Supreme Court decisions, a Canadian Constitution plus Manitoba's Constitutional law branch directing us with WRITTEN RULE. The Wildlife Act has no application to aboriginal or subsistence rights on land that aboriginal or subsistence people have a right of access so your question(s) would not be answered in that statute.
The Manitoba Métis Federation (MMF) provides harvester cards to its members who have proven their Métis genealogy. The Province recognizes harvester cards possessed by MMF members in certain parts of Manitoba. Again all these decisions have been made by the Supreme Courts and/or Constitutional Law branch.
The Manitoba Government must abide by these high court and constitutional decisions. By the same token, it does not recognize harvester cards in areas outside the boundaries established by the Supreme Courts and Constitutional Law branch.
If you don't want "non-license" people in your boat or other vehicle that is your prerogative!
In the event that licensed (non-subsistence) and subsistence people share a vehicle or boat, any fish or wildlife taken by subsistence people CAN NOT be shared with non-subsistence people.
I've been in this field for 35 years and it has been illegal for subsistence persons to share their harvest with non-subsistence persons for longer than that! The only thing that is different is that some Métis people now have a subsistence right in some areas of Manitoba.