1) MPF is 100% counted into income and 100% taxable, not only tax on capital gain2) whether it is taxed or not, it depends on whether you have already withdrawn and received money in your bank account before you became tax resident of Canada
3) for inland it is complicated as you cannot withdraw before you have COPR (MPFA only accept foreign passport or confirmed PR as proof, but if you are inland, the process will skip the COPR step hence you have nothing to show MPFA to withdraw