Yes I would keep him separate a while longer to see if he can learn to walk better before putting him in with the others to prevent him getting trampled. Does he seem to be drying out and fluffing up or is he too sticky yet? PICTURES OF THE LITTLE ONE?!?!
You said he is sticky. I would give him some time to finish absorbing the yolk, if he survives that then in a day or two I would then try to wash the sticky off him- I have had a couple sticky weak chicks that really perked up after a bath got the sticky off them so they could move better.