Retirement tax questions

Yes, you can Efile adding the income under 'Other Income' and claiming a Foreign Tax Credit if you paid tax on your Canadian Pension.

If you are not using a 'Substitute 1099-R' (which can't be Efiled), you shouldn't have to describe what type of pension you have.  You only need to enter a description/amount. 

The income is taxed the same way, whether Pension Income or Other Income. 

As you probably guessed, the main difference between a public pension and a private pension is the employer. Public pensions are available from federal, state and local government bodies.  Since yours is a Canadian pension, if it was issued by a branch of Canadian government, you may have received a tax break on Canadian tax due.