I think there are some GREAT suggestions/discussion on this board. I hope some of the developers are reading this.
Super abilities need looking at, but I don't agree with your suggestions.
The Super Diplomat and Super Breeder abilities do NOT need to be made more powerful in any fashion, as they are already ridiculously good at what they do.
I agree with much of what astral has said but I think Starstriker1 is very correct here. I generally like to play on high difficulty levels such as obscene or suicidal. So far, the only races I can survive with are the Torians and the Terrans. The Torians massive economy allows you to survive the early game colony rush (by essentially being able to fund it), allows for espionage to steal techs (which on occasion enemy races seem to have without researching prerequisites), and to buy huge class ships to instantly fix defense emergencies. As the for the Terrans, the super diplomat ability with all the races on the map (including 8 minors) promotes just enough tech swapping and convincing of other races to war with each other to survive and even prosper.
(Granted there are some obvious remarks to be made: if there few races you are playing with then super diplomat is a waste and if you're on a tiny map, the super breeder trait isn't so great on only one planet. In these situations, it would seem like the Iconians are quite effective.)
But yes, the Drengin are a poor choice (even though still powerful) in comparison to the Korath. Further, what I see in all these high level difficulties is that the Korath ALMOST ALWAYS dominate... It's actually quite entertaining to watch. (I recommend it. Put yourself on an immense map with the suicidal difficulty and watch them spread like wildfire). I think on these difficulties, their economy is doubled or tripled if I remember, so their upkeep problems for their production buildings are nonexistent. Anyways, they would be unstoppable if it weren't for their dumb tendency to being fooled into warring with every single race on the map at once (hehe).
As for the temple of memories, yes it is useless. I always go straight to healing pools without any hardship and just build these suckers on each planet as needed.
The super adapter doesn't make sense for the Iconians. Especially when the Yor can colonize Barren, Korath can colonize Toxic and essentially, the Torians can colonize Aquatic so early.
I noticed that no one commented on many of the more (nonsuper) traditional abilities
which seem useless or ineffective such as: range, espionage, sensors, trade/trade routes, courage. I could give many reasons for this but I've already written too much.