Will my WordPress site become vulnerable after adding this functions which allows more HTML tags for subscribers?

Read here about _moz_dirty (Using Google would have given you the same answer – 2nd Result for “_moz_dirty”). Regarding html-stuff: You’re offering the ability to add links…

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)