MC is probably also an reality warper but sees himself as just anormal human that got powers from Sam so he doesn't show any standard array powers because he thinks he has non.
sam said exactly the opposite. both are psychic, and his inability to control the MC is tied to that. otherwise he will be jumped in his clone wihtout sending the protagonist in the hospital.
About the control thing Sam explained that he can go "full control mode" on someone, but wouldn't use it often because its like a hammer to the psyche of the other person, also MC isn't proficient enough (yet) in direkt control to do it and he doesn't have the power needed (for now).
you are mixing different things.
the thing sam don't usualy bother it's puppetering. it's the ability to control the body of a person, without controlling their mind.
usualy done by telekinesis.
the other two form of mental control are enthrallment and revision. sam is most proficient in the first. when you take control of the body of someone by interposing between the mind and the body. the third is what the protagonist do in the dreamwalk.
permanent change in the psyche, changind
de facto the person mind
going "full control mode" mean you rewrite a mind from scratch, totally ereasing the person was before to replace by something the psychic want. but doing so will leave trace, and that trace will be spotted, soon or late, and this mean all the mentalist (super or villan) of the world will declare a truce and will hunting the rouge psychic in the most ruthless way [sam explicit said "going weapons free and scorched earth"].
this mean no. don't, simply don't.
MC is far more proficient in making mind connections and sleepwalking which Sam can do but not in the capacity MC can with so little power output (Sam would need magnitudes more power to do the same).
sam it's probably the most powerful telepath in the world. so he can, but his power are ill suited for something like that. so he don't bother. and i think mantain permanent connection with people mean tied togheter that people to him, and i think he see most relation to casual to going that commitment. he don't gain clear advantage by doing that, it's will restrict his personal freedom to much, so he don't do that.
MC power are basically focused on connetion e psychic link. the amount of construct you can build depend on the number and the strenght of the connections made. his power set works in this way.
Sam tells the MC that he cant get energy from mind connections like the mc because holding them would negate any energy he could gather from it and the more connections he is using the higher gets the drain. So what MC is doing right now would drain Sam already.
to drain sam power reserve [when alive in his body] will need a fuckton pile connection. he speak of nearly balance between the energy he can gain trought the link and the energy required to keep the link working.
mc link are of the highest precision. because is power are highly polarized in that directionl.