Is using Bound Sword's for a conjurer mage a good idea? At the moment, they are doing plenty of damage but at higher levels, will the conjured weapons be any good against higher level enemies? Or would it be better to invest in smithing perks and skills instead and save the conjuring for atronach's and dragon priests?

I checked on another character and his damage output was really low with a conjured sword! Does it get better, by any chance? (I have Mystic Binding on that character too).

Only the bow is any good at higher levels. It's the same as an exquisite daedric bow, with 100 daedric arrows... but free!