DB + beholder buff

Does dragon blood stack with beholders w.att buff or not?

Yes, but only when hex has a higher wattk than db. Hex retained it's "smart" property and won't buff if something higher than it is active.

So in other words its not worth maxing out dragon blood when I grind with a crusader with max rage all the time, am I correct?

DB is 25 wattk and rage is 20 wattk. From that perspective it's better to max DB.

Hex will stack with any other buff lower than itself so if you wanted to you could leave DB unmaxed and just go with rage but you'd need to carry around pots for when your buddy wasn't online or when you try to solo anything at all.

Your other options for 3rd job aren't nearly as enticing either. It would allow you to max both ER and Magic Crash but how often is ER actually useful?
Max DB, even if you don't use it all the time it will come in handy.

If I wasn't clear earlier hex and db do stack when hex is maxed. The only time you run into issues is with lower level hex.

Ok, I'll leave ER at lvl 11 then I guess, thanks.