@Anup *********
yes, we pay income tax in Canada on this income, although it is possible at this point to initiate the steps to become non-resident of Canada for tax purposes, and thereby minimize taxes.
It is possible to work in Thailand with the LTR Pensioner visa but as I am not interested in doing this, I didn’t look into it . You should contact the BOI and ask for clarification. There is also information about this on their website.
Finally, we were asked to provide evidence of income for the past year only and that is what we did in order to obtain our visas. I don’t see why it would all of a sudden be evidence of 5 years’ worth of income when we go to renew in 5 years. I see nothing that indicates this so I doubt that is correct and would love for someone to show me otherwise. That said, our income is fairly stable generally speaking so it is not something we need to worry about so we did not ask about this in our conversations with the BOI.