I know this is an old post but just started with SIms 4 and was looking up this topic of keybinds.
The answer here interested me, I don't know what type of keyboard has a numeric 0 that is bigger than all the other keys, and to clarify what I'm sure the person this was a response to was saying, 1 for pause makes so much more sense, then 2,3,4 for normal, fast and super fast.
0 is all the way at the end of the numbers so is just odd placement.
This is the way most games I have ever played have ever used the keyboard for speed. A few having space as pause instead of 0.
Minor quibbles overall, Sims does have a lot of fantastic options, just baffling to me what changing even basic keybinds is not one of them.