well my sister took the golem tower quest at level five and took her two years to complete it. i am saying this because i think golem tower is to advanced for the less expierienced wizards i'm just saying because i have a level 24 or 25 wizard and still am not up to it. and i defeated grubb and he had 1,000 health.
i defeted golom tower at level 4. all you have to do is defeat the wooden constructs and then use a potion to heal then if you need help again use a fairy :D
Golem Tower was pretty tough for me. I did it when I was around Lvl 13-15. I don't remember... Anyway I just got some treasure cards like meteor strike and humongo frog. That did the trick for me. But I agree with you unless you think you are able to fight constant battles without anyone's help do not try golem tower.
Golem tower isnt required, although I would recommend you do it for the badge It isnt that tough, just use rank 1 or 2 pip spells and a pixie every other fight to keep your health up.