What does this below rebus puzzle mean?

Railroad Crossing, look out for the cars. Can you spell that, without any R's ?

What is black when you buy it, red when you use it, and gray when you throw it away?

If two fifty-foot ropes are suspended from a forty-foot ceiling that is twenty feet apart, how much rope will you be able to steal if you have a knife?

A Child was born in Lahore, Pakistan.

Still child is not a Pakistani citizen.why ?

Where do you go to learn how to make ice cream?

What is the longest word in the dictionary?

What does Alexander the Great and Winnie the Pooh have in common?

With the help clues provided in the image, can you find the 5 digit key?

Let's play a word game. Following are some meaningless words that can be completed by adding random letters on either side of the word.

For example, the word "rdo" can be formed into "pardon".

Using the same technique, can you complete the given words?
ecalc
airb
rinci
tibac
uidel
gorit
igna
eyho