I should've probably noted that I'm on Linux, so I'm not sure if the Windows version runs better. Every now and then I run into some games like that, most of them made in Unity. It wouldn't be that big of a problem if it didn't make aiming that much more difficult though.
As for the sprint, I did notice you can't sprint backwards (without a perk) but still ended up simply holding down the button 100% of the time because why not. Good to hear that you already have plans to change it.