When it comes to Apple a blue screen is never a good sign. Normally relating to either Logic board damage or Water damage.
There are some ways to trouble shoot the device though!
If the blue screen is occurring continuously you may want to attempt a restore on the device. As long as the data is not a factor or if you have an iCloud back up for the device I recommend the restore.
After the restore, if you are still experiencing the blue screen there may be damage to the board.
To prevent this issue from happening remember to:
1. Always be grounded when touching on or near the logic board of you device.
2. Keep your screws in order and place them back in the exact spot you removed them from.
3. Don't over tighten your screws. Ever.
The digitizer being unresponsive can be couple of things:
1. A defective part is a possibility, if you have another screen on hand give it a try.
2. I know you have already taken it out and placed it back in but make sure it is connected properly.
3. Finally, if it is related to water damage or logic board damage. A water cleaning or logic board repair may be needed.