Hmmm? Why the sigh? Seems like a perfectly good build to me, and could be really good with burst damage at high levels, but it wouldn't be too broken since you could only add 26 damage at most.
Considering an average PAM Paladin/Sorcerer using a Quarterstaff can easily have AC well over 20 and do 2d6+1d4+15d8 in a single round, this seems fine.