or for example

move resurrect and sacrifice into the water
Dimension Door - into fire (two jumps on expert, raise price to around 40-50)
magic mirror - set percentage to 50% on basic, on advanced 50% and cannot be dispelled, on expert - 50% for all and cannot be dispelled; it would be good if upon casting it removed already cast garbage (curses, slows, etc.) with the same probability
raise the price of fly slightly, for example to 25 or 30

regarding all other spellbooks, changes in wt (minor movement across levels, change of prices, change of spell power) - ignore them; they are entirely correct decisions moving in the right direction