It is more like 70 at the max, 49 would be the norm. You can keep leveling all you want(till every skill is at 100) but the game was designed for 1-50 characters. I think it is lame that you don't have a level 1 perk, start people off at level 0 in the intro if you need to.
BGS said soft cap at 50 and much grinding to get past that point. Also, as you said the game is not balanced for character who go past that level.
With that in mind, I think it is somewhat fruitless to plan above 49 perks. If the game is not balanced beyond level 50, while you can put in a lot of work to get past it, your choices will matter less and less since there is nothing harder out there for you to fight. You could start the Destruction tree after all your melee stuff at lvl 50+ so you can experience a different combat style, but it is not really going to advance your character since they will already be at the zenith of game power, and everything else will just be turning the slider down, I think. Maybe it is worth it on hardest though?
I honestly think aiming to get game defining perks around lvl 30 will be best.