Dancer or Singe/Bard - there are artifacts the may let you use instruments which does nothing in combat except a continous animation of your character playing the instrument. There is already Piedpipper class under archer base class that uses flutes.
Reaper - IMC had scythe weapons in GE but they are recognized as 2handspears in-game. I believe most other game simply place scythe as 2hand spears for programming ease. A vampire themed class would probably be related to Dracula-ish so its rather more practical to have them wield swords. Since ToS is following historical classes for Swordsmen tree.
Samurai- its not self explainatory, all swordsmen, can wield katana, just look at the database. What would a samurai specialize aside from just wielding a katana. besides from above a katana is simply categorized as 1 hand sword for ease of programming.
FFT samurai class abilities depends on what sword they wield. it would be horrendous mount of work for programmers to program each single sword
Martial Artis - why not simply just place another weapon type gauntlets as 2 hand weapon and add classes under that use gauntlets.
Engineer or Machinist - there is probably one mostlikely as all steampunk fantasy titles will have one, but mostlikely hidden class
Astronomer - you play too much FFT
