Yes. Every sentence begins with a capital letter. No exceptions.
No. It is a common noun, not a proper noun.
No, seasons are not capitalized.
Wikipedia is capitalized.
Have should be capitalized if it is the beginning of a sentence. Summer should not be capitalized.
No it shouldn't be capitalized.
No it doesn't require to be capitalized.
No, seasons are not capitalized.
"Can" is typically not capitalized in sentences unless it is the first word or part of a proper noun.
Yes, "Spring 2009" should be capitalized because it is a specific season and year.
No, keywords do not have to be capitalized.
No it's not capitalized.
No it shouldn't be capitalized.
Wikipedia is capitalized.
No, it is not capitalized.
(a "pilgrim" is a religious traveler - the term is only capitalized when directly referring to the "Pilgrims" who were the settlers of the Plymouth Colony in Massachusetts beginning in 1620, either before or after their arrival in the US)"The pilgrim stopped at many desert communities on his way to Mecca.""Their religious beliefs established a strong work ethic in most Pilgrim settlers."
Occupations are not typically capitalized unless they are used as part of a title before a name (e.g., President Obama). Otherwise, they are usually written in lowercase (e.g., teacher, doctor).
Have should be capitalized if it is the beginning of a sentence. Summer should not be capitalized.
Yes, the word "astronaut" should be capitalized as it is a proper noun referring to a specific job title or profession.