Taking kayaks into Canada from USA

I'm going on an extended car camping trip in the Canadian Maritimes,
carrying two kayaks on the roof. We'll probably be storing some of the
lighter gear in the kayaks (sleeping bags, pillows, life jackets, etc.),
due to limited trunk room in the car.

Any issues crossing the border into Canada with this rig, or upon return
in to the USA?

Any issues with vessel registration? Neither of these kayaks (one 17',
one 14') must be registered in my home state, so they have no numbers on
them, no title, etc. My understanding is only powered boats must be
registered in Canada?

Do I have to carry regular boat safety gear (flares, whistle, lights,
etc.)? We will be just puttering around in these in campground areas,
not running expeditions, so I would not normally carry a lot of safety
gear (we always wear lifejackets, boats have flotation chambers or air
bladders, etc).

Just don't want to be surprised by any unknown regs or restrictions at
the border or during use in Canada. We will be going to New Brunswick,
Nova Scotia, PEI, and Quebec.

Thanks for any info,

NSS