I've had a lot of friends but these two friends are the only ones I can count on andto be will always be there for me.
This first friend is a guy I have known since grade 7
...."guy" sounds a bit too slang...however, it depends on your purpose. If this is very informal writing, then it's fine. Otherwise you need to use a more formal word like "boy".
This first friend is a guy I have known sincegrade 7; He was a transferred student who recently moved in the island.
... grade 7 and recently - the reader tends to get confused about the times. The first one gives the impression that you've known him for long and the second one disturbs that feeling.
I laughed, hearing someone still says that in this age (stop here)andAgain I thought it was nice even though it was kind ofshowed his straightforwardness.