Your skill caps are wierd. Pending your class, you have 3 stats that go up at every lvl. In my case I'm an eldritch, so my Int/Dex/Qui all go up when I lvl. Your cap is 1.5 times your lvl, so at lvl 30 you can have 45 extra points from items. I'll give you my example. My eldritch is lvl 32, so i can have 48 Int points from items (1.5 x 32 = 48). At 32 my base Int is 113, so my skill cap for int is 161 (113 + 48 = 161). Buffs are a different story. As far as I know there is no cap as to how high your stats can go buffed. I'm currently reaching Int as high as 190's and up; however my int is still capped at 161 unbuffed.
I hope this helps.
~Turraslo