You transportation questions might get better responses on the West Coast Embarkation board.
As for car rentals, no idea if there is a location that you may use.
Uber & Lyft, I believe, have larger capacity vehicle that should accommodate the scooter.
11:30 seems doable, but could always be a gamble of sorts; ship might arrive/dock late, traffic issues; whatever. You need to make sure you have an early disembarkation slot.
Fastest exit is to carry off your own baggage - not great - unless you figure you can handle it through the crowds, elevators, gangways.
They organize different slots for exiting. Again, make sure yours is early. NCL transport can get you an early slot and should accommodate all of your stuff, but pricey for 6 people. no idea what taxis/Uber costs but you can look that up online.
Also, again, ask some of these questions on the West Coast board.
My only experience with Vancouver was as an inbound passenger for an Alaskan cruise.
However, I've never heard of a passenger going through immigration while still in transit. As long as you are within the airport concourse(s), you should be fine. Only passengers exiting the secure areas are subject to "entering" the country. Just because you are continuing to another Canadian city shouldn't matter. Double check, if you like, with your airline.