Request for passport stamping & foreign travel form

I just got the news that the high commission in NewDelhi has requested for my wifes passport.They sent the letter on 28th Nov & I received it on the 19th Dec, here in canada as I had given the mailing address here.

Quick questions

1.does the 30 day clock start from the day they posted the letter or the day I receievd it which happens to be the 19th in my case?
2. They have included a travel form that needs to be completed & sent to Immigration. This has two sections, principal applicant & spouse/partner. The principal applicant here happens to be my wife for which I shall fill in the details. Do I need to fill in my details being the spouse of the principal applciant or leave that column blank as this just might be a general letter used for all sponsorships.
3. can my wife physically go to the high commission & get the passport stamped rather than sending via courier?

thanks in advance

Arvind