Hey , hobble i can squeeze out an answer , and more will follow
1- multiple pots in a smaller size is a better idea , because if you screw up one big pot , your done , if you screw up 2 out of ten smaller pots you will have 8 more chances
2- more pots are better because you can experiment with multiple techniques and strains
3- multiple plants in one pot , bad idea , they struggle for root space
4- get a handtruck to get plant out the door , but you already know that....
5 - multiple pots better when you encounter pest problems
6- large pot requires more nutrient solution , and if you use , and the plant is too small , you will waste costly product
8- yield will depend an experience and skill , many experienced growers will pull out more bud from a 1 gal pot than some can pull out of a 15 gal , just get started and you will get a feel for yield