The idea about promote a youtube channel with bitcoin giveaways isn't bad at all, we love giveaways, sometimes i make some of them in the Spanish section. But i think for this one we don't have the right clues to solve it, we don-t even know what part of the privatekey is scrambled... if you could tell us the number of characters who aren't scrambled that would be a good hint.

But puzzles are this way, i will wait until OP gives more hints to try to solve it, with the actual information is impossible, other way someone should already found that privatekey.