Street skating and park are definitely going to improve your kiteboarding skills.
If you can hit a handrail skating you can hit any slider kicker there is for kiting.
Not to mention skating is alot more precise, you actually have to land stuff or you get rolled, so you might actually grow a sack if you skate a bit

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Skating will also dramatically improve your balance, lets face it you don't really have to balance kiting at all, you just lean against it.
You will probably start skating and realise that you can go skating wayyy more than you can go kiting... Not to mention it's a hell of alot cheaper.