For example, my pure is 63 combat in a pvp world, If I decided to get summoning on my pure, would this affect my combat ONLY in non-pvp worlds? Or would my combat in pvp worlds also be affected?

Your combat level would only be affected in PvP worlds when you're actually carrying a summoning pouch, or are using, or recently used a pouch. In other words, if you train summoning, but don't use it, your combat won't be affected on PvP worlds. You'll get the extra combat levels on PvP worlds when you actually use the skill.

I see, Since I have a Raven egg on my pure, I could get summoning, just so I can hatch that?

 

Good stuff, finally a use for them charms on my pure :P

 

 

 

Thanks