This question might sound nooby but its something i really wanted to know

How does skills that affect movement speed such as flail and charge works together? Flail gives -33% and charge gives +33%. Does it negates the speed reduction from flail?
Other examples will be flail with enchantments like Flame haste djin.
Oh and also how does increasing movement speed works when you are crippled? Does it works the same as the flail vs charge?
Thanks