The socks are for my feet of course. About the summons, they're with you all the time, like a normal party. You can have up to three with you at any time [four character total including yourself]. So later you have more than three, you swap them in and out of your party through the summon menu.
Happy birthday dude :). I don't quite get what the socks are for but hey I don't judge. As far as the game goes the customization system sounds awesome. About the summons tho. Are they with you at all times or do you have to summon them during battle?