A comma before "too" is up to you! Usually we don't use a comma before the word "too" regardless of where the word appears in a sentence but both are grammatically correct. If you want to emphasize the word, as you might be likely to do in your second sentence, then you should add a comma.

I would tend to use: "I would like to do it as well" or"I would like to do it also" "It's nice to meet you as well" or "It's nice to meet you also" If you did use" It's nice to meet you too" or I would like to do it too" it is correct and there are no commas

No,it is not needed.

Strictly, yes, but in practice no. You would only use the comma add emphasis, but you rarely see it in general use.