Whilst on a study permit 20 hours a week any more than that would be illegal although during scheduled breaks you can work more hours but only during scheduled breaks.
Impossible to answer as that is dependant on the course you take and the college you attend. Could be May/ June through September for example so maybe 3 months but has to be a scheduled break in a 2 plus year course.
Cannot do a 1 year course take a break then do another 1 year course, in the break in that case you would not be able to work at all part or full time during the break.
