1) Slow, defensive, can hit hard, good at sitting on close objectives
2)
Good matchups: non battletome armies, other slow armies
Bad matchups: the rest
3) Not necessarily and imo a grudge if you do so
4) Teir 2.5. Definitely not teir 1 with daughters and legions, teir 2 with nurgle and others you will struggle but can win against, teir 3 should easily be able to win
Note none of this matters if the game modes has a bunch/moving objectives. You will lose.