regarding your questions:
Q: can I change my last name before reaching a decision to my application?
A: reach out to CIC and they'll give you the best answer.
consult this webpage about changing names:
https://www.easynamechange.com/ca/name-change-checklist/Citizenship-Permanent-Residents/
it is said: "Any Canadian Citizen or permanent resident can change names. This may be a name change from marriage, divorce or a legal name change.
The name change can’t be done as part of your citizenship application. You must follow the same name change process as all other Canadians, then apply to get your citizenship certificate or permanent resident card updated. When you apply to become a citizen,
the name you provide on the application form will be the same as your name on citizenship. There are no name changes allowed during this process. You can apply for a legal name change either before applying for citizenship, or after citizenship is granted."
Q: I know that once became a Canadian citizen I automatically renounce my Filipino Citizenship not unless I apply for dual citizenship is this correct?
I can d so without having any complications entering Philippines one day with a Canadian passport and my name being switch back to fathers surname?
A: it is better to consult your embassy webpage or go to see them directly, or ask someone who is Filipino too and had the same case.
the same webpage above talks about changing name and possible implications in your country of birth.
Congrats for receiving your AOR!
Good luck!
