what is the recomended level for the add-on, dawnguard was a level 10, im thinking this one is a bit higher.

i had trouble at 51 on Adept but i svck at skyrim

I don't know what the game requires for it but I would recommend 20+. A lot of the bosses gave me quite some trouble.

I would say at least level 20 playing on adept. My woeful Orc warrior was a level 25 and struggled, but he is just hopeless at surviving so that was nothing new for him I got him to level 27 before running for home and giving up. A normal level 20 character who can fend for themselves should be able to get through it. Being good at sneaking and archery would make it easier.