If you're stuck on Pro because there are Master songs you can't beat this event (or because you can't beat them well enough to get an encore), and it's way too easy, I recommend doing songs with one hand. It doesn't make it as hard as Master, but it does up the challenge a bit, at least on a tablet.
Personally, I think the healing skills give too much back, but that might just be me. As long as you don't hit a OMG wall, it gives you way more during a song than Life Up bonuses. If you've got a horde of recovery/damage guard idols, Life Up only increases the number of mistakes you can make in a row by like... maybe two or something.
... And seriously, I gotta be the only guy who doesn't change speed in any rhythm game he plays.