I disagree with freezing monk's stack timer on bosses because even though it is annoying, monks are balanced around losing their stacks a few times a fight. It is also a good thing for monks to lose their stacks at a few points because it makes openers and burst more important overall instead of just sustain in the same way that add phases make AoE more important.

However, I completely agree that skill/spell speed should improve resource regeneration rate as well. All other stats improve your character without penalties with the exception of skill speed. In most cases, skill speed feels more like a punishment than a benefit as you just run yourself out of TP and need more songs, or have slow your attacks down negating the stat.