Hey Olga, there is no better choice than Cape Town for a kiting holiday!
As far as kite friendly accommodation you can try SaltyCrax Backpackers, Windchasers and The Endless Summer Beachhouse. All run by kiters, for kiters. You can find full details here http://capetown-watersports.com/accommo ... cape-town/
Blouberg, Muizenberg and Langebaan have a wide range of kite spots, activities and restaurants which are all super affordable due to SA's weak currency.
As to safety, If you look back to the 2010 world cup and the amount of tourists in Cape Town since then, you will see that Cape Town is geared towards giving tourists a fun, safe experience.
You can find all other info here http://capetown-watersports.com/