Speed is very important. Shaels >> all of those Jewels.
You can't upgrade it any further... there are only 3 classes of weapons, WWS starts as Exceptional, upgrading it once makes it Elite, the highest it can go.
WWS isn't really a Frostmaiden weapon either... it's got no +bow skills, so your Freezing Arrow will be weaker. If you can get your hands on a Lycander's Aim, it will be much better than WWS for your Freezing Arrow damage.
Since it is your interum bow just socket the bow with what suits you. If you are not happy with it, Hel it out.:wink3: Take a look at this little beastie I made with two junk? jewels and mediocre WWS. 70 off weapon IAS is easy(9/3),110 (9/2)shouldn't be that hard to get either.