Yes. You could have put commas after Howard and Center, but they are not strictly necessary.
Short answer : Yes and not impolite at all, as suggested below. This is to be handled by you grammatically correct? requires inverted commas to be correct. It should be written as: "Is this sentence "This is to be handled by you." grammatically correct?" The sentence is correct but not very polite; it would be simpler to say "You are to handle this"
The sentence "When is it your birthday?" is grammatically correct. The subject "it" refers to the specific day that the person's birthday falls on, and the question is asking for that information.
This sentence is not grammatically correct. For the sentence to be grammatically correct, the space between "in" and "to" would have to be removed. Therefore the sentence should read "They are into skating."
"That was wrong" is a grammatically correct sentence.
Yes, because "from the Cancer Research Center" is an appositive, and it must be set off by commas. Jane Howard, from the Cancer Research Center, gave me your contact information and suggested I get in touch with you. Appositives refer back to the subject and give more information about the subject: Amelia Earhart, the famous woman aviator, died mysteriously in 1937. There are also some people who would suggest another comma, after "information"-- gave me your contact information, and suggested I get in touch with you.
The sentence is grammatically correct.
The sentence "Rhoda's Crazy" is not grammatically correct. It is missing a verb to make a complete sentence.
Yes, the sentence is grammatically correct.
Yes. A grammatically correct sentence (to begin with) has to have a subject (int this case, hand) and a verb (is). The sentence does need to be capitalized and punctuated correctly though...
Yes. Strictly speaking For example at the beginning of a sentence is what is called an "absolute," grammatically unconnected to the rest of the sentence.
'What a drunkard you are' is a grammatically correct English sentence.
Yes, it is grammatically correct.