Not really. The "under development scheme" is particularly wrong.
This sentence is grammatically correct.
Yes, it is.
You had not taken that into account. Would be the grammatically correct version of that sentence.
Der Junge ist rothaarig is grammatically correct.
It can be, like in the following sentence. There were many firsts in this historic week.
"That was wrong" is a grammatically correct sentence.
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."
The sentence is grammatically correct.
yes
The sentence "Rhoda's Crazy" is not grammatically correct. It is missing a verb to make a complete sentence.
The sentence (not sentance) is grammatically correct
Yes. "I do not like people" is complete and correct, albeit anti-social.