for your question about the interview :
from what i read on this forum, the interview can be done in 30 mins to 2 hours, it's different for everyone and it depends on the VO (visa officer)
they will ask questions about your wife, your relationship, her family and ask questions about how well you know about her and her life; they will ask about your future together and what you plan, and they will ask how you will do if your application is not successful .... these are only some of the things they ask about because it is different for everyone
here some questions they already asked people who passed the interview (i got this questions from this forum)
do you know why you are here?
when was the first contact with your wife?
how did you meet her?
who made the first contact?
what is your wife's name?
what do you call her? (I think this was because in all our emails he calls me val but my full name is valerie)
how old is your wife?
(they asked him my age, then tried to correct him, but he stood his ground and they said "yes but she will be that age in a few months", which is not really true, my birthday's not until the fall. i found that interesting)
when is her birthdate?
where does your wife work?
what does she do there?
she's lived in different countries, what has she done there?
do you know your wife's family members?
what contact have you had with them?
have you travelled together?
where did you travel together?
did you have a honeymoon?
your wife is divorced, right?
what do your family members do for work (brother, sister, parents)?
what do you do for work?
noticing our receipts for sending money back & forth:
does your wife send you money because you need it?
did you send her money for the same reason?
do you have family in canada?
are you still in contact with them?
but in general, u can expect any question from them. best of luck my brother.. Rebi m3ana kamline
but at least this is just 4 weeks inshaAllah. ;D