Potential =/= basic individual. A Protoss has the potential to singlehandedly make an entire planet's population collectively bleed out the eyes, nose, and ears with a powerful psionic assault.
Goodbye brains, hello scrambled eggs.
Plus, if enough of them got together, they could literally move planets across space-time.
but what makes you think that Dark Templar can match a Jedi when lowly zerglings, marines, and firebats can kill them?
A) It's a game mechanic. Given opportunity, a Marine can kill a Battlecruiser. In the books, which are actually realistic (or as realistic as it can be in a fantasy universe), the Dark Templar don't show up much but when they do they're pretty much untouchable. Generally the normal Protoss make asses of themselves trying to track them down while the humans go "lol wut wuz that?"
B) They're powerful as ****, but not immortal. Fire, claws, and Gauss spikes will kill them. It's just damn hard to get a lock on them to be able to get a good strike in. I don't give a **** who you are, even an Archon gets owned if he's assaulted head-on by several hundred Zerg. Luck and circumstance can tilt against a Protoss as well as in his favor, too.
You're kind of painting Protoss as Gods. If they were so awesome they wouldn't have lost to the Zerg in Starcraft and Brood War nor ally with lowly humans.
The Alliance was very, very, very reluctant. In fact, only Tassadar and a few others were willing to do just that: "ally with lowly humans." We're kinda inconsequential to them. Hence the fact that we first became aware of their presence when they nuked the **** out of a few of our worlds because they had Zerg on them. The Protoss never gave a **** about us until Tassadar took our side, and even then not so much until we started fighting back.
As for the invasion of Aiur, that was a really really bad circumstance. When Zeratul killed the Cerebrate Zasz his mind briefly linked with the Overmind, who drew from it the location of Aiur. Once the entire ****ing Zerg Swarm knows where your homeworld is, you're ****ed. There's a reason they
won the Brood War, the Zerg Swarm in its entirety is pretty much unstoppable. Plus, the Protoss were so damn busy fighting amongst themselves that they practically let the Zerg walk right in. Pride is definitely the sin of the Khalai.
Plus are the novels even canon? If so Toss are going to be imbalanced as **** in SC2.
Pretty sure they are, yeah. The SC2 website actually references some of the events in the novels in the unit histories and descriptions. Don't remember exactly where, but it's accepted as canon. The novels were officially sponsored by Blizzard...as in requested to be written.
And the Protoss will be no more imba or OP than they were in SC1. Blizzard doesn't let lore conflict with game balance. The game will kinda throw "how it would really go down" to the wind when it needs to be balanced.