it sounds to me like everything is fine...does your incubator circulate the air?
no real need to candle until day 18 but don't expect to see a whole lot they get very quiet about that time
in chick development 10 more days is a llllooonnnggg time so don't get discouraged
remember broodys gather a clutch so they may not sit regular for several days...it's hard to determine exact due date because of that but incubation is technically the same
30% is actually fine
I do the dry hatch so I don't add water unless the humidity goes below 25%
when you need to raise it you can add blobs of wet paper towel some add a bowl of water...just depends on what kind of room you have in there....I've known some that spray water through the vent hole...