Réponse:
a. you should spend mire face-to-face time with him
(should: conseil)
b. they must remember to include everyone (obligation)
c. you may go out with your friends (permission)
d. he can play basketball better than anyone ( aptitude physique)
e. I think you shouldn't have skate in that driveway(reproche. on pourrait enlever le "I think")
f. they mustn't go to the mall by themselves (interdiction)