I did every branch my first run using multiple saves and I don't think it took more than about 100-120 total.
Z2 is pretty fast compared to a lot of srw games. @3 is taking me yeaaars.
I usually watch animations here and there and on bosses/new attacks, but during the middle map grunt waves it's almost entirely animation off.
A lot of it is Japanese reading speed as well. For me 50% of my game time in srw is reading the pre and post map story.