It's not wrong, if a bit effusive.
Another view: It is correct and good. Memorable means easily remembered, and very is an intensifying adverb, properly used to intensify an adjective. I would certainly use the phrase "very memorable" to describe something which stays in your memory.
It's correct English but not very good English
it is not correct English, you rather say still
It is correct.
It would be more correct to say, someone who.
It is correct English to say decent skill but not decent ability
The correct way would be to say "you are very welcome."
It is correct English to say "He went off on a tangent".
no it is not correct to say you are not for sure instead you can say in proper English that you are not sure about something
No. In English we say "How old are you?"
Yes, it is correct to say out of compliance with. It means out of help with in English grammar.
In American English, the correct form is "two hundred sixty-four", although "two hundred and sixty-four" is very common.In British English, the correct form is "two hundred and sixty-four".
No, it is not proper English to say "on tomorrow." The correct phrase is "tomorrow."