1) It's possible. On their website, it says:
You can sponsor:
* parents
* grandparents
* brothers or sisters, nephews or nieces, granddaughters or grandsons who are orphaned, under 18 years of age and not married or in a common-law relationship
* another relative of any age or relationship if none of the above relatives could be sponsored, and you have no other relatives who are Canadian citizens, persons registered as Indians under the Indian Act or permanent residents and
* accompanying relatives of the above (for example, spouse, partner and dependent children).
So since you are not orphaned and under 18, you don't fall under that category but I think you would fall into the "another relative" catagory as long as your grandma has no such living relatives as listed in the first 3 categories. Check out
http://www.cic.gc.ca/english/immigrate/sponsor/relatives.asp - it has probably most of the info you need.
2) There is a minimum income listed to sponsor people, you can find it in the applications forms/guides.
3) You can find some processing times at
http://www.cic.gc.ca/english/information/times/international/09-fc-other.asp4) I don't think it matters with family sponsorship if you have education. Are you supposed to stay in Canada for a whole year on travel visa and are you allowed to be working there? If no, it might hurt your case rather than help it.
5) When granted PR while you are out of the country, they normally give you an expiry date on it. On mine it was one year that I had to show up in Canada or it would expire. Of course you can come to Canada, do that paperwork for the landing and then leave again if you have some pressing business elsewhere. If you give your grandmothers address, they will mail your PR card to that address. To keep your PR status, you need to live in Canada at least 2 years out of every 5 years.
6) To apply for citizenship, you need to have lived in Canada as a PR for at least 3 years out of the last 4 years.