Float tests don't tell anything unless the egg floats and it wiggles. High altitudes are harder to hatch in. I can share ifo on high altitude hatching, but it is hard to follow, but you might find something in there usefull...
65% humidity for the first 17 days is extremely high for table top incubators. I will almost bet that the chicks drowned. I seldom see anyone hatch successfully with humidity that high. As a matter of fact, I am always amazed with the handful of people that claim to have success at 50%+...
There is not anything you can do for them unless they are able to pip themselves. At day 25 I would not expect to see more action. Hatching at day 25 is a big sign the temps in your bator were extremely low, I'd say 2-3 degrees. The lack of others hatching could be due to the delay weakening...