Is using bitcoin for savings a risky choice?
Buying bitcoins shouldn't be thought of as savings, it's a very high-risk speculative investment. It could go way up in value, or way down.

Luckily, if you want Bitcoin's power of secure storage without exposure to the exchange rate, you can do that too, in theory at least. Use most of your funds to buy X bitcoins, and use the rest as collateral to short-sell X bitcoins. You'd have to pay a bit more for the exchange, pay an interest rate, and trust some of your money with the platform, and there aren't currently very good margin trading platforms, but it can be done and might be worth it if you're sufficiently averse to the traditional alternatives.