Thanks! The mouse acceleration feel might be that you look around more slowly when sprinting. The spike trap thing seems like a bug and I'll work on it. The durability of ranged weapons is kind of a mix between ammo and actual durability, but I left it as one number to keep it simple.
And while that salesman did wipe the floor for you, he might've just taken some of the treasure to sell it back to you too.
There's a lot of things to discover in this game, not only item-wise, but mechanic wise, and I hope you have fun mastering it.