I test crit rate by using Bear Surge + x. If it's 100% then x must be at least +25%, so then I'll switch to 3 Lagu Sharp Edge Cards + x. With this, there should be minimum 85% crit rate; I just stack Wolf's Bane: Fanged (5% crit rate) thereon. It only took 2 Fanged's to get to 100% so I'm pretty sure it's 30%, if it's not, anyone feel free to correct me.
And Sky Conqueror is 20%, and It seems that Hercules is +5% for each skill level.
Also as a side note, from what I've gathered, there are different % caps. There isn't a flat cap of 30% bonus, each damage category has separate % increases. Aerial % boosts, Ground % boosts, and Overall % boosts are all considered different, so at any given time you can stack up to +60% damage increase.
Sorry if old. .-.
Life doesn't imitate art, it imitates bad television. PSN: ZanSangyou