1. No in-person interview. Google cic canada to learn about applying online for single-entry or multiple entry tourist visa. Upload all the required forms and documents. You will be asked to mail passport once you are approved online. Total process could take 2 months for the canadian consulate at Los Angeles.

2. Hard to say which is a safe choice for h1b stamping. Most of the time, if you are a full time employee, you can visit Nepal instead. However, if you plan to marry a girl in Nepal but work through a consultancy, i suggest you have your visa in Canada that way you dont give false hopes to your girl, just saying :)

3. Location in canada:
Fast processing: Ottawa, Calgary
Medium: Toronto, vancouver
Slow: Montreal
Google us visa processing time and use these cities name to check how long each consulate take to process h1b visa and the same site gives when the date are available. Note: dates are running out fast. The actual dates can be seen after you fill out ds160 form online pay the fee, and try to take a visa interview date at US consulate. Make sure you give the loomis address in the same city as the consulate because thats where they will send your passport.