Why only magic? It's just as unfair to not get any other perk if you're waiting for it. That means you have to change all of them, or none of them, to be fair to less-magic characters. Perhaps adding a rare perk "Upgrade of your choice" or "Magic upgrade of your choice" in addition to the current perks, rather than replacing them?
Added it to the top post, for whatever good it will do
I didn't directly witness the effects of this, probably because my difficulty was set to low and I never fought anyone, but in the end game report, the mana bar for one of the AI civilizations (Gilden) jumped to an obviously erroneous high number. And if I'm to believe the graph, he made use of it all somehow... <a href="https://dl.dropbox.com/u/1
I just realized (after having played lightly before) that you can upgrade objects built on a resource (mines, farms, etc) after you get certain research. It would be really nice if there was a cue when that becomes available, as there is when a resource comes into your domain.