Experienced hatchers -we need your brains!

Wondering what the protocol/steps are for a successful hatch! Last year, before I was knowledgeable, I set a bunch of eggs in the incubator, kissed them fondly, wished them luck, and had a great hatch rate. This year, trying to be more 'correct', ive monitored humidity, closely watched temperature, and have the eggs in a turner. Im suffering hatch failure - out of about 25 eggs, due to hatch yesterday, I have 2 pipped out at about noon today, but no successful hatching quite yet... Just wondering what Im doing wrong and if anybody can please help me! SUPER depressing! I got a digital thermometer (reading 98.6 at the very bottom of the incubator) with 75% humidity. No air circulator though? Please help! Wondering if taking them out of the turner and laying them flat on the incubator could be causing failure? I realize the temp is a little low too, but with these thermostats in the Little Giant bators, Im terrified to keep cranking it up because I dont wanna bake em! I candled everyone, and they all seemed grown... I did notice that this hatch, at day 19, there seemed to be some vein involvement at the top close to the air pocket, which seemed slightly immature for the stage they were at.. Idk, sorta at a loss and thinking of switching to lizards!

 

Humidity during incubation varied between 55% and 65%.

 

Yes. Definitely have candled eggs. Im positive these were developing appropriately, however, unlike others at 19 days, I noticed veins next to the air sac. I commented at the time that these eggs seemed to be less mature. I realize the temp is too low Im just reticent to crank it up and bake them... Everything I read indicated that a lower temp would slow hatch rate, and a high would kill it.. I figured since it was recommended at 99.5 that 98.6 probably wasnt terrible. This was my first time using this fancy digital thermometer, and since its heavy, it sits at the bottom. I also assumed that the temp probably is higher on top of the eggs and its likely closer to 99.5 at the top of the egg... Im not unwilling to wait... I definitely saw 2 eggs rocking yesterday, and now 2 different ones are pipped out.. At this point, will turning up the temp fix it!?

 

Air cells seem large...since the chicks have pipped, I havent opened the incubator again in case I kill them...If I turn it up, will it correct the slowness? And, I misspoke...the humidity during incubation ranged between 47%-55%, and now its between 70-75%. Any opinions on removing them from the turner and causing an issue? Should I also let them hatch upright?