Basically, yes, the weapons you can earn from the void within plot are very good. Some are a matter of preference or maybe fighting style, but the Wand of the Dark Faerie is considered one of the top weapons to have.
As for the lingo, damage done or blocked is measured in icons (there are several kinds of icons), so something that does 10 icons worth of damage is probably better than something that does 6. The reason icons are used instead of numbers is the actual amount of points of damage you can do depends on your neopet's strength level. A low level neopet will just do 10 points of damage while a higher one can do 150 with the same 10 icon level weapon. So winning battles depends on your equipment plus the training you've done with your neopet.
There are plenty of minute details and rules to entertain/bore a person for days (just like baseball or the stock market) but that's the basics.