"Thank you to my colleagues for... " is fine as you wrote it. Your next two almost ok! try this: "Thanks to the three of you for helping me" or "Thank you, all three of you, for helping me" As for 2) "I wouldn't expect anything less from you" means something like "This is good and I am not surprised because I would expect it to be good coming from you." Your standards are high, or your work is always good, or .... Meantime, "I wouldn't expect anything more from you" suggests, "This is not so good and I am not surprised because I would not expect you to do something great." Meaning, your work is always limited, or your devotion is limited, or ....

"I wouldnt expect anything LESS from you." Is a compliment!! It's saying "I knew you were the best so I'm not surprised!" :) "I wouldnt expect anything MORE from you." Is NOT a compliment! It's saying "I knew you weren't good enough for the job so I'm not surprised." You do NOT want to hear that!

In response to question 1, Yes. You can absolutely use that construction.