Unless your project is gluing marshmallow Peep bunnies together, then your task of bonding rabbits is undoubtedly going to require significant persistence, consistency, and patience.  If you are constricted by a tight schedule or are faint of heart, then having a single bunny might be of preference.  And yes, bunnies can live happy lives without the company of another bunny as long as they are given ample attention from their owners.

The first major obstacle in bonding rabbits is the gosh darn pesky hormones that cause them to be incredibly territorial and eager to mount anything of remotely spherical shape.  I do not recommend even attempting to bond your rabbits until they are both spayed/neutered and given 4-6 weeks for the hormones to subside and balance. 

This is a loaded question, and the answer really depends on a multitude of factors.  I will say, however, that one of the biggest mistakes parents can do regarding first pets is to make a hasty decision to buy a bunny for their young children (toddler/preschool/young elementary age), especially when they assure me, "My child is ready to learn responsibility."  Well, what happens a few weeks into the "responsibility lesson" when your child loses interest or discovers that bunnies don't like held or carried like a kitten might tolerate?  Someone else ends up taking over the responsibility, and the bunny may end up neglected, seen as a nuisance, or even worse, surrendered to a shelter.