I like the idea of having a per level scaling based on attributes (and not simply based on leveling) that could be really cool. So in your example, a level 15 character would get X bonus from stats 15 times? Where X could be +weight carried, + heavy arm penalty reduced+% damage and accuracy (but in small numbers)
However,
You start with the 30 needed to have a minimum 5 in each stat, and then another 50 or so to distribute as you see fit.
Every few levels, let's say level 3 and every 3rd level thereafter, you gain one extra point.
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If you start with 80, and you get 1 per 3 levels, leveling won't change a thing about your character ever and you might as well just stay at what you started with and give no points/level. Nobody is ever changing their mind about what they want their character to do unless they are doing the math on 30+ stats available through gear which to my mind is not only a nightmare balancing but also a lot of extra work anytime an item drops.
If your starting distribution was maybe 10 points and you got one new point every three levels, things would feel more static and 1 point would also mean much more, both at creation and when leveling.
However, that also requires a complete rework of the current stats and the current math, changing itemization, leveling structure and power/level.
I think a more measured tweak is needed.
