So if the spacecraft accelerated at 1 G both there and back while the other twin was on Earth also experiencing 1 G then they should be the same age? Their clocks should tick at the same speed relative to each other?
No. Gravitational time dilation is related to differences in potential of the gravitational field and not to the magnitude of the acceleration. For example, in a uniform gravitational field there would be no time dilation experienced based on changing position in the gravitational field.
I knew I was wrong, I was just curious WHY I was wrong, so thanks for the correction.