Sorry to hear that you are having so many issues. At the end of the day you will need to find a way to extend the wire, you simply do not have sufficient length to connect everything properly.
If you can not find any slack along where the wire run takes a turn or comes in from outside, you may need to buy a wire terminal like this (link) and a short length of irrigation wire like this (link).
Alternately you can simply unscrew the Rachio from it's current location and move it down a few inches to give yourself enough slack, the difficult part will be to trim the protective pipe without damaging the wires.
I'm still not sure why you feel like the wire(s) need to be bent, you may wish to get a short length of practice irrigation wire and try different angles to find how to insert / remove the wire without bending the copper core.
Finally I am curious about the number of wires in your picture. You've bought an 8 zone version, but I count 9 red zone wires (not counting the Master valve 10th wire), is one of the zones unused?