The xp chart is an easy one. From the d20 system guide...
"No Covered Product may contain rules or instructions of any kind that:
• Describe a process for Creating a Character
• Describe a process for Applying the Effects of Experience to a Character
Specifically, Applying the effects of Experience to a Character means incrementing the character level of a character by incrementing a class level by one rank, or by adding a new class at first level, and describing how to allocate new skill points, select new feats, select new talents, or gain new class-level linked abilities.
Applying the effects of Experience to a Character does not include creating or modifying an experience point chart, defining a new class (including describing what benefits that class provides at each level)."
So, yes, you can modify an experience point chart.