In reference to the character animation speed, I’m guessing your reffing to different skeletal meshes? In this case you’d have to setup different blend spaces, and here you could adjust the range of speed values the animation blends with. In this case id imagine you’d also want to adjust the characters max walk speed and acceleration in the character movement component.
If you
Ex: my project allows the player to morph between forms, some faster some slower. I have a hot bar widget setup that sets the players mesh, anim BP and movement speed on selection of desired form. All of these values, and a few more, are setup in a data table, that has the corresponding row called and values plugged in to the morph form event chain functions.
Hope this helps