How are you adjusting mash pH? How long was the steep? A good steep should reduce the need for bittering hops.
It looks too me that your water has low inherent buffering capacity. Adding minerals for buffering could overcome that but would likely result in a minerally flavor. I agree with making a post-fermentation pH adjustment, but it may already be too late to restore the desired hop character. In any case, you could use the data gained from your post-fermentation pH adjustment to make a preemptive adjustment at the start of fermentation to prevent loss of hop oils during fermentation.
You could also change yeasts and see what happens.
As to entering into competition, I doubt the judges would be able to give you good feedback about changing your recipe/process as they don't know what your recipe and process was.