I didn't have a religious ceremony either. I explained that we are both catholic and my husband was married before and the catholic church does not recognize divorce, so we could not have a religious ceremony.
I would rephrase the part with his parents not attending the wedding because it's an expensive trip. I don't think it would sound good if you would say your in-laws are to cheap to be there at their son's most important day
Maybe try and have them and your husbands friends see the civil ceremony live through Skype or Facetime or something similar and mention that. And mention again that they are involved in organizing your big wedding in Canada.
You've met his family online. So it's not like you've never talked to them. Have them write a support letter anyway, it's important. Make some snapshots during video conversations through Skype/Facetime, include some of the discussions you and his mom had over Facebook, especially some of the more private ones.
This I don't think it is really an issue. I'm in the same situation and it never was an issue.
Yes
Unless there's a really big age or cultural difference between the 2 of you, I think you will be fine ;D