Thinking...
If you get +2 the first time, and +1 on every level you decide to invest in a particular skill, by level 20, you're still going to be around +20 above somebody who hasn't invested in a skill. This can create quite a large difference between somebody who has invested and somebody who hasn't, which can cause problems if they want to make the math flatter.
It might be better if they limit the bonus gained from skills. Let's say one can't get any higher than +10. If one wants to still invest in the skill, maybe have the option to spend a level's worth of skills to "master" a skill they have +10 on. This could mean something different for each skill. For the Swim skill for instance, perhaps this could mean that they no longer have to make any more Swim checks, regardless of the conditions.
If you get +2 the first time, and +1 on every level you decide to invest in a particular skill, by level 20, you're still going to be around +20 above somebody who hasn't invested in a skill. This can create quite a large difference between somebody who has invested and somebody who hasn't, which can cause problems if they want to make the math flatter.
It might be better if they limit the bonus gained from skills. Let's say one can't get any higher than +10. If one wants to still invest in the skill, maybe have the option to spend a level's worth of skills to "master" a skill they have +10 on. This could mean something different for each skill. For the Swim skill for instance, perhaps this could mean that they no longer have to make any more Swim checks, regardless of the conditions.