You did a fantastic job! sometimes you can't save them all, but if there is a next time you will know how to deal with it. How are the 3 chicks doing? :)
You have done very well by them, many would have just tossed the eggs given the trials you had.
Chicks don't know any better and you are now 'mom' so they will be happy and well cared for. :)
Well done you!
If you can keep them warm to 90-95F the first week then decrease by 5 degrees each week they will do fine. I think your improvs' have worked well so far, no reason why it shouldn't continue :)
Wow! Kudos to you for trying...
1. you need to get the temp up to 95F at least, not sure how you would do that in the oven...
3. humidity - yes you need it otherwise the inner membrane will 'shrink wrap' them. Humidity > 65% - 70% is better.
4. can't think of anything other than an incubator
5...