I know you've had this thread up for a while; I may as well give it a cent or two.
I for one would like to suggest a slight upgrade chance for each stat- be they the new basic ones you've suggested, or more detailed/derivative ones- if they predominately or exclusively are invested in at the expense of others.
For example, if I invest entirely in haste, while neglecting all the other four stats, then after reaching a level with haste, haste from then on would rise a little faster with use, and/or be proportionately more efficient to "buy" via points. From then on, I can increase haste further, faster, whereas the other stats must be hard-pressed-for as always.
By contrast, if I were to balance my character, keeping haste in a stone's throw of each of the other stats, then no bonus (or penalty) would apply and the levelling system would work as it does by default.
Lastly, in this system I imagine, the more specialized the stat is, the greater the bonus for future levelling becomes. For example in the above... example, focusing solely on haste will give it a better bonus than, say, also investing closely in muscles; but, raising just those two would still give each a bonus if they can significantly outpace the other three stats. In turn, raising muscle and haste would give each of the two, when they get high enough, a bonus better than if I were to raise, say, muscle, haste, and sense together. Still, raising these three would incur a slight bonus if made high enough.
This would allow, and encourage, players to specialize a character in a particular way, if they choose. If anyone wants to make a juggernaut meathead that moves like a turtle but can take any hit and smash anything, including out there in the 300.0+ level fog, they may do so more easily; if we want to make a speed demon who can run from the graveyard to the cabin in about five seconds, and who simply runs circles around whatever threat comes along, we can push for that goal; and I don't know what "sense" will be about, but whatever it is I would like to try it and make a game mode/character exclusively revolving around it. Maybe you can do for this "sense" what Bethesda neglected to do for Illusion and Alteration in TESV. I certainly trust you more already.