Genetics help to some degree, but the most important thing is the mind and the spirit. These two are even more powerful than physical characteristics that are passed on.
I love to be sore and when I feel sore I train even harder.
Yes it is better to keep training even if your muscle is still sore.
Eat a lot and train hard, I am sure that you will succeed.
A bodybuilder is a sculptor who carries with him his own material.
Trust me when you love something you don't need motivation.