What happens to your CPP/EI contributions when you change jobs? Is your portion of the contribution carried over to the new employer? Are there any taxes involved?
No matter what your job, the CPP and EI are paid centrally to the federal government, your new employer will continue to deduct under your same SIN number and report as such.
What will not transfer as far as I know from one employer to the other is the amount paid so far this year for total deduction purposes.
Therefore, at the end of the year, when you have two T4 forms, one from each job, you fill the total CPP and EI in the appropriate slots. If you have overpaid, compared to what you should have given your income, then it will be directly refunded (or offset other taxes owing).
There are no other taxes - not quite clear what you were asking in that third part.