I think it's great you like your marmoset. I truly hope you can be a good family for it.
However, despite your "research", you really have no idea what you are in for with just the experience of five months and only one animal. It's a bit presumptious to recommend to someone else that they consider ownership, when you don't know that person (although Jess is a great pet owner) and you really don't know much about the animal you are taking care of.
I know a little bit about captive primates too. For instance, I know that the marmoset you have now, is nothing like the animal you will have when he becomes sexually mature. During the first year or so, they are cute, tractable, sweet and loving. The perfect substitute for a baby human. In five years, it won't be like this, ...not at all.
Here is a quote from a web site for exotic veterinarians:
People often ask about the differences between marmosets and tamarins. The differences can be classified in 2 different ways. First, taxonomists distinguish the differences between marmosets of the genus Callithrix and tamarins of the genus Saguinus by their teeth. The incisors of marmosets are enlarged, so that they are the same length as the canines which enables them to gouge holes effectively in trees so as to consume the nutritive gums and saps (called exudates). The canine teeth of Saguinus species tamarins are longer than the incisors,1 which means that they can inflict a deeper bite. Because of the differing lengths of the tamarin's teeth, some government organizations have classified tamarins as more dangerous animals than marmosets. While the tamarin's teeth may allow a deeper bite, it is the innocent-faced marmoset that is much more likely to chomp a human's face, ear, or nose! This defines the other way that marmosets and tamarins may be differentiated. As far as aggression goes, it is the marmoset that is usually more aggressive and dangerous! Hand-raised marmosets are quite fearless around humans. They may actively and aggressively defend their territory and their owner against strangers and family members. They may quickly jump to a visitor's shoulder, then launch an attack on the face or ears. They usually bite quickly, but the bite is prolonged, meaning that once they bite, they do not let go. Sometimes, they bite, and keep chomping down, causing multiple bite wounds in the same area. Other marmosets bite toes, hands, or knees as the preferred sites. On occasion an enraged marmoset may bite its owner in a case of misplaced aggression when it sees a person it considers a threat. A tamarin may also attack strangers or a person it perceives to be an intruder to its environment, and it also may bite family members that it does not like. A hand-raised callitrichid is quite fearless around humans.
Like any puberty-driven teenager, there will be hormones, conflict, territoriality and, ...in this case, there will be biting as the animal seeks to become the dominant member of the family. Then when it's mature, no strangers will be allowed in the house. Please come back then and tell us how it is.
What I think is most telling about pet primates is what the people that take care of them, professionally, think about them.
In working over 20 years at a large, metropolitan zoo, I've known all kinds of keepers. Almost every herp keeper I've ever known has had their own collection of herps. I've known many bird keepers to have extensive collections of birds (I was one, and I still have quite a few birds). I've known hoofstock keepers to keep things as exotic as camels and zebra. I even knew an elephant keeper that owned his own elephant for a short time.
However, I've never, ever known a primate keeper that thought that keeping pet primates was a good idea. The primate keeper I married, spent 20 years taking care of everything from Tamarins to Orangs to Gorillas. She loved every day of work with them. We even raised woolly monkeys in our home for awhile. No one who works with them would want one. When they are no longer babies, they are like irritable, unpredictable, 2 year old humans with fangs, claws and no rules or boundaries.
Admittedly, a marmoset will never tear your face off like an angry chimp, but they can be pretty destructive and inflict some respectable wounds. But, to say they can be good pets when you've had hardly any time with this animal is foolish.
Check out: Monkeys As Pets
In my experience, the only people who will tell you they make good pets is either 1. Someone who wants to sell you one, or 2. Someone who really has no idea what it's like to take care of a primate long term.
Sure, there are a few people who can manage good, private primate ownership. ...just like there are also people out there who are professional soccer goalies and who have played in the World Cup. ...I've never met one those folks either.
I really, honestly hope you are one of those people. Not for your sake, but for the sake of the animal that you have chosen to take into your care. I hope your stewardship is better than you describe it. Equating it with having a kid in one sentence, then calling it a pet in another. Describing an inadequate diet. Encouraging others to get one, when you, yourself have no idea what you, yourself, are really in for. You really ought to get to know what's in store for you, before you start trying to recruit other folks. Primate ownerships isn't for just anyone, ...I'm not sure it's for anyone. I'd like to see you prove me wrong.