Garm is one of the best PVM mvp cards for low/mid rate. On Woe/BG, when they're taken serious, it's junk.
You can mix strip[if you can even use it there without problems -> no creators around with fcp] with fsk or just copy ice bolt and use it with a elemental sword equipped.
If you need dex or not, it's up to you and if your build needs it or not.
Full Strip has no cast time, individual ones have a small one. The extra chance and duration times that you get always depends on your dex-enemy's dex so, vs high dex users = adds pretty much to nothing.
If you still want to check about it and if it's worth or not, you can always use the link at my sig and check the values at the calc [AFAIK, they're accurate].