Apparently, from knowledge and basic observation (non tested), this is all I that I understand.
In PVP, character level does matter. No, higher character level does not give you advantage, its the other way round. If your level is lower the the enemy in PVP, you gain some 'unknown bonus' base on the system, I guess this is to balance out level differences in PVP.
PVP def (not the def stat but PVP def), works for both phy and chak attacks. So chakra damage damage is reduced if you have an amount of PVP def.
Lastly, I know many people have assumed or took it for granted that every 100points in the stats is equal to 1% chance. But I beg to differ. I am guessing it runs on a non-linear scale but instead a log-scale. Meaning to say the initial 1k evasion gives more evasion than the subsequent 1k evasion the character has.
For better understand, all fabricated numbers but to picture it,
1000 evasion > 20% evasion.
2000 evasion > 25% evasion.
Why I think of it like this is because my crit attack stat is about 1200 but it increases far more than 12% damage in a crit hit. My crit rate is 2100 but it somehow doesn't feel 20% at all. Your post just made me think that maybe my conjecture so far has not been wrong.