Re: League of Legends - Your questions answered.
Riot does sell power, though they out and out deny it.
Runes have a hefty impact on the game and can only be purchased with IP--someone who purchased champions with RP will have a significant advantage over someone who's using IP for both.
Riot counters by saying this is a choice that players make, that you don't have to own all the champions, etc. While this is true, I still see it as a minor form of selling power....that said, once you're of a moderate skill level and level 30, this problem pretty much evaporates....it's more of an issue from levels 20-30 and lower skill level 30's.
Overall game balance is "ok", but Riot has the mentality of "is something strong/cost efficient/used too much? Nerf it" instead of "perhaps we should introduce a counter".
IE: Old old Twisted Fate would have been fine with a few number tweaks and the introduction of TP scrolls, but Riot canned TP scrolls in alpha.
Oh, Riot pretty much hates strong auras...because, according to Zileas, a +200 damage aura is only mildly more appreciate, by players, than a 50 damage aura, while being way more *actually* impactful on the game in actuality.
That said, despite this, they allow aura stacking, orb stacking (of the same item even, in some cases), and few others cases....they're starting to come around on this a bit, but it's still on a case by case basis.