Good point about Evasion, although they are not the only class to get that feature. As far as Balancing on a cloud, without trawling through the books for numbers I'd suggest that by the time you were high enough level to do that, not only would you have used a hefty chunk of skill points (and possibly a feat or two) but magic items and/or simple spells will equal or better that ability every time.
What I liked about sneak attack is that it got the lightly armored guy to race into combat to make a key blow. They had the skills to do it (tumble) and the class appealed to people who liked calculated risks. I just liked the idea of doing it to the Drow Lich as well as the annoying High Priest.

Balancing on a cloud was the highest DC in the epic level handbook (120, IIRC). Maybe magic has it beat, but it pointed out the extremes to which the rules could bring mundane abilities.
Which is one of the gripes with 3.5 model, and time will tell whether Paizo are inexorably sucked down the same black hole due to player pressure. In 3.5, take a class feature like Track. Who gets it: only the Ranger, and it is his *thing*. Somewhere, accompanied by a string quartet of the world's tiniest violins, a player of a wizard has said 'but I should be able to do that with a spell!'. An enterprising soul at WotC has thought 'hmm, if we write one up in a splatbook somewhere then the party will be able to compensate if nobody at the table plays a Ranger - everybody wins'. Well, except the player of the Ranger, who sees one of his core abilities eroded, turning him into an even more useless warrior - because, yes, people can whine about the rogue's inability to sneak some things, whereas the Ranger is a featless fighter, whose class ability is a whopping +2 damage (and +2 on a load of skills, some of which he's not very good at anyway) vs 1 type of creature. Got a great idea for a character whose favoured enemy is outsiders of the Earth subtype? Good luck getting much us out of that in the game, buddy... Oh, and let's not forget a combat style that's not only perfectly accessible to any other class, but which he SOMEHOW FORGETS HOW TO USE IN A SET OF PLATE MAIL!
Somehow no edition post-1E has had any idea how to create an interesting Ranger. The 1E ranger worked really well and had notable abilities which were unique and interesting (including fun trade-offs like a d8 but more HD at 1st level and more HD at peak) plus tracking abilities that couldn't be duplicated. When the game got more systematic, they seemed to lose inspiration for the class and it never really recovered (until, possibly, 4E).
Again, to be as fair as I can to Paizo, they said they wanted backward compatibility with 3.5 so they were kind of stuck with a number of millstones/albatrosses round their neck. The sneak attack tweak was simple and easy to implement so it was kind of a no-brainer - for the record it's the way sneak attack is implemented that bugs me more than anything. But I'm afraid there is an element of 'the emperor's new clothes' about some of the supposed balancing that has gone on with the class tweaks in PF. The 'weak' classes have had a new paint job but under the hood their basic function and the way the rules support them is fundamentally the same - you can't polish a turd as they say.
Personally, I'd have had my cleaver out and made shoes and stew out of some of the supposed sacred cows of 3.5.
I think that this is the key point. One could imagine a rogue class that looked more like the AD&D thief (which still had the cool backstab ability). Paizo had a tough choice about how to rebuild the system to work close enough to 3.5 that it kept the old base but try and change small elements. Whether a more complete re-imagining of the chasis would have been a better idea is a very good point.