1) Is 470 critical rate equal to 17% on crit on all skills?
Yes sir, you can do some research around and see by yourself that 500 crit is ~20% crit rate. I can't really be totally precise here if its really what you want, but I can dig the data I found on Bluegarter forums, between others. Anyway, my point was : Adloquium is crit capped. All the other heals aren't.

And somehow I find it to be normal, otherwise Adlo would simply be too powerfull