The reason Sasuke is so about not being in a squad is because it had been such a long time since he'd had actual friends that he'd forgotten what it truly felt like to have real friends.
He distanced himself from Ino and Sakura the most because he knew how they felt about him,and he didn't want to hurt them. He knew he wouldn't treat them right and hurt them in some way, thus the reason he called Sakura annoying when he left;that was the way he admitted that he liked Sakura back.
