Yes, if it is the first word of the sentence.
NO...
Yes, you do.
No. There is no word in English that always requires a comma before it.
no there is no comma after the word because. there is no need for a comma in the sentence at all.
Yes, if followed by a comma.
No
Not necessarily. The comma indicates a pause in speech. Use a comma after "but" only to indicate a noticeable pause in speech. If there is no pause, there should be no comma.
Your answer depends on the context of the word instantly.
Yes, such as when writing a letter.
yes
In many cases, the word 'however' is followed by a comma. The problem with the word is that one must be careful not to over use a comma. However the word is used,(note that there is no comma used in this connection) the word itself frequently does not need a comma as an automatic punctuation.However, (meaning 'on the other hand') phrasing will most often determine if the word is followed by a comma. These two instances here are examples of when to use or not use the comma as punctuation for this word. When the word is used as a substitute for the phrase 'on the other hand', it is most often followed by a comma.
Typically, there is no need for a comma before the word "as." However, using one is not technically wrong, just superfluous.