That's a lotta spells, and for the most part, you're going to get a bunch of varying opinions unless you make the system more or less complicated. Oh, and then we get into spells that have multiple versions/usage such as Wizard Haste or Trapsmith Haste? Do the options for Pyrotechnics work at different efficiencies?
Instead, i suggest the following system:
T1: Cheese (Or, the stuff your PbP DM has on his ban-list) i.e Ice Assassin, Shivering Touch
T2: The Best Stuff (Basically stuff that does the best of what it should do) i.e Grease, Glitterdust, Haste
T3: The Good Stuff (Basically stuff that does what it should do) i.e Fireball, Shield,
T4: Specialists (Stuff that does what it should do, but solely exists to solve a specific problem) i.e Divest Essentia, Dispel Ward
T5: Utter Trash (You spent *how* much lead writing this!?) i.e Bigby's Tripping Hand
T6: Variable (You know, we honestly don't know where this goes, but it goes somewhere) i.e any "Image" spell