Bringing back Jiraiya from the dead would be too predictable.
What we need now is a revived Hanzo to fight Naruto!
- quickly master various jutsus
- use basic forms of nature manipulation
- see chakra
- see through reanimated corpses' visions
I am very sure Pain has used his Rinnegan to his fullest extent. You're forgetting also that complicated jutsu are a combination of two or more different elemental attacks. Besides, the fact that Nagato is using jutsu that he developed surely implies that his jutsu are stronger than ones he has already encountered, which leads to deduced speculation that his jutsu are self-proclaimed "the strongest".
I don't remember "eating chakra" either.
Also, the Sage of Six Paths (the first one with Rinnegan) was also the first one to use ninjutsu. I believe that statement actually means something significant to Nagato's power.