you know, i doubt they would "not allow" the larger scooters. my father-in-law requires a larger scooter due to his weight/ health. and although he is a very proud man, and is embarrassed when he boards the bus "first", he needs one to be able to accompany his family on his vacation that he...
no, you don't have to notify the resort. i write my reservation number and check-in date on the label. you can send packages back at the front desk of the resort.
we took our son at 5 1/2 months. we didn't take him in the pool, our choice, so i really can't answer that.
we did take him in the infant carrier into the restaurants with us, we didn't take in the stroller, just the carrier.