It is better to see the previous Special Case Examples before following the answers to the given questions.
Answer:
This language is similar to language
Only one difference is there that range of x but it does not matter because x is not part of our given language.
Because we know all finite language is a regular language.
Answer:
But we can write regular expressions for this given language.
Because we can write regular expression for it.
Answer:
This language is similar to the previous example
But the position of the x is different which does not affect the type the language.
Answer:
This language is almost the same as the language
This is Regular Language the only difference is the range of ω which does not affect the type the language.
For details see the previous example Special Case Example: Example 4.