There are two Arcane Blade guides on the forums right now, one is for dual wielding which I wrote (
viewtopic.php?f=52&t=38775) and the other is for shields which is also good (
viewtopic.php?f=52&t=38786). Since you don't have Stone, Fire is good too since it lets you get the awesome Flameshock spell. For points refunding, you can always unlearn the most recent four class points you spend (most recent three for generics). This means you can put 4/5 in Lightning, then refund them when you want to learn something else and then put 4/5 back into Lightning so your most recent four spent points are always in Lightning. If you have any most questions that the guides don't cover, you can always ask the game chat since there are lots of helpful people there.
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My wiki page, which contains a guide and resource compilation and class tier list.