Yes, it should be capitalized when it's part of a title.
If you are writing something with a title, you would capitalize Happy Holiday Season in the title. If you are writing it in something other than a title, you would not capitalize it.
Yes. It should be Season's Greeti ngs.
Yes, the season "Fall" should be capitalized when used in a sentence as it is a proper noun.
At the beginning of the sentence or when it forms part of the proper noun or when it is used in the title. Example: Warm this Season
Yes, you should capitalize "Fall of 2008" when referring to the season in a specific year because "Fall" is a proper noun denoting the season and "2008" is a specific year.
No, "holy season" does not require to be capitalized.
Yes, I would capitalise Easter, but not season, exactly as you did.
Yes, season names are capitalized when writing.
No, "fall" should not be capitalized unless it is used at the beginning of a sentence. It is a common noun, not a proper noun.
It would be more appropriate to capitalize the season name, so "Zevalin Fall 2008" would be correct.
Seasons are only capitalized when they form part of a title.
Yes, "Summer" should be capitalized when written as "Summer 2007" as it is part of the name of the season and is used as a proper noun in this context.