When people who have never clicker trained a dog give out book learned advice on how to clicker train a dog, the recipient of the advice will often try it out, it won’t work because the advice is inaccurate. The owner will then think that positive training doesn’t work and go to the dark side.
If you want to clicker train your dog, go to a dog trainer who has used the techniques successfully. Certainly wouldn’t take advice from someone on an internet forum who may not have any experience of actually doing it.
For example if you were to use a clicker, you have to do a fair bit of ground work before you start. You can use any reward your dog likes - food, or toys/play will work. The time to click a dog on the recall is when he is running back to you and not when he arrives at your feet. You click the dog when it is doing what you want - not when its finished the action.
A 7 month old colliexstaffy is going to be high drive and challenging to train - he needs a job to do to channel his energy. You also need to ask youself what your expectations are of him at this age and get some professional help to acheive your goals. Still chewing at this age is quite normal - keep your good stuff out of his way.
His constant need to play - if he needs to play and get rid of some energy.... well he needs to play so you have to give him an outlet for that. You can't expect him to sit quietly when he's bursting at the seams to play. As well as physical exercise he needs mental stimulation. Remember that collies are bred to be work all day long, they can work all day stalking sheep and never get bored with doing it.