My idea for an improvement in skills and stats is very simple.
The ability to specifically set a limit on skill gain. (Using numerals and/or slider, like the split item system)
For example: You have 90 points left to spend in your combat skill tree and you want to spend it on 60 in 1 thing and the last 30 points into another. But you "overlevel" your first skill to 60,8 and cannot get your last 30 points into the next thing, where you end up with an useless 39,2 skills and is unable to progress correctly.
This would allow you to effectively remove any unnecessary decimals by setting a maximum skill cap on your own progression.