>The value of it fluctuates so much that actually buying/accepting it seems incredibly risky. The price can go down just as fast as it goes up.
Why? If someone sends me 1BTC I'll just instantly sell 1BTC, it is tremendously unlikely that I'm gonna get screwed even if there's a 1-2 second delay.
>if the value of a BTC is going up, why would I use it to buy anything?
Because you want things and not numbers on the internet.
>As someone looking to accept BTC for purchases, how do I do so with confidence that when I accepted $3400 today that by the time I cash out it's not worth $2700?
By being smart and not waiting to cash out. Your maximum loss will be the value of whatever buffer coins you hold, and I guess you could hedge around that too.