Regex Guru

Hello, This is an urgent task, I need someone immediately and the tasks must be completed today. I need someone to find the right regular expressions to: 1/ Replace multiple empty rows with 1 empty row. So, if we have this in the original file: This a paragraph (empty row) (empty row) (empty row) This is another paragraph We'll end up with: This a paragraph (empty row) This is another paragraph Be it 2, 3 or more empty rows in between. 2/ Replace multiple empty/blank characters with only 1 character. So, for example, if we have: This is a sentence. (3 blank characters between "This" and "is" here) It will be replaced with: This is a sentence. 3/ Remove blank characters if they start or end a line. 4/ Remove any blank row we'd have at the very top or at the very bottom of the documents. 5/ Sometimes, on my files, the closing p tag of some sentences are on the next line, like this: < p >This is a sentence < /p > I need to move the closing p tag at the end of previous line and remove the empty line below, to get this: < p >This is a sentence< /p > Thanks in advance. Best regards, Florence.