Those are feeder roots and it's a good things that they're up by the surface like that. Don't worry about disturting them, they are some of the hardier roots the plant has. Obviously don't fuck with them too much for no reason but you get the idea. You're fine with the pinching, some of the best growers I know don't use any tools at all, just pluck them with their fingers. No worries about bugging me bro, this is what I do for a living. I'm glad I can help someone put some chronic in their life! 11 liter with those size of plants will be just fine all the way thru flowering. I love big pots, but I've seen some monster plants grown from itty bitty containers. Just a preference I guess... Good luck man and hit me up if you need anything else...
W.C.C.