So if this doesn't have any charges on it, can you still use the action ability since it doesn't require charges to use?

That is a correct assumption.

So even if I don't have charges to spend, I can still use the action ability to make a hell of a good evasion attempt. This seems a bit misworded because of how good that is.

A level 4 card being really good should be the norm though, right?

Sure, but most spells aren't useful after they run out of charges, this one still is.

That is certainly odd and as such is an obvious candidate for errata.

That said, while it can make Sefina an evasion machine, evading itself isn't that useful a thing to do, and at 4XP I think it will struggle to get into decks.

I could see it needing to say "while there is a charge on suggestion..." And, if the wording on the card is the original intent, I don't see how this would struggle to get into a deck at all. 4 points for an almost guaranteed and reusable evasion is huge, even if there's hunters around.

4 skill points in other classes gets you a lot too though, and if you have good enough combat skills or naturally good evasion you don't necessarily need it. Skids for example is only getting a +2 to an already solid 4, why would he spend 4 exp for it? The option to ignore attacks is the big thing I'd say, particularly the attack of opportunity used when you are attacked and get your weapon out. Assuming you don't have that fast event in hand...