GRE

Hi
All information you required is listed out here for USA. Other countries like canada do have rolling admissions so the best is to shortlist universities and then apply.
http://www.studymsinus.com/list-universities-offering-ms-misismismitm-us/

Yes, and besides you also need to learn German language.

Both are totally different streams and both have different scopes, comparison therefore is not possible. Just choose the one that you are really passionate about. Don't listen to people around you and get confused, otherwise you will go haywire. Just think, realize follow your dreams.

Any one from each.
Regards

Hello, well it depends where you want to study. Not all universities require GMAT or GRE. As an international student however you must take TOEFL or IELTS.
Regards

Hi Namish,
Kindly, specify what do you want to study?

Dear Anis, GRE scores make a difference if it is mandatory and depends on what you want to study and also your grades cum profile.

No, they are not compulsory but having either one of the scores is an advantage no doubt.

Use Arihant series for verbal ability development

yes it is accepted