DND_Reborn
The High Aldwin
I think it looks good over all. I (sort of) agree with @Stalker0 about the spells, but I would make it spells with a single component (V or S... I don't know of any that are M only) is fast, then make all other spells slow.
Alternatively, to regress back you might want to make single component spells fast, and all other spells d6+spell level? In a lot of ways, I do like tying speed to spell level so casters will know their super spells will likely happen at the end of the round. If you do spell interruption (personally I would) then it allows for interruption during the "casting", starting at the die roll, ending just before the spell goes off.
Ex. A casting of Fireball would be d6+3. If the player rolled a 4, the spell could be interrupted on a 4, 5, or 6. On 7, the spell is done and cast.
Alternatively, to regress back you might want to make single component spells fast, and all other spells d6+spell level? In a lot of ways, I do like tying speed to spell level so casters will know their super spells will likely happen at the end of the round. If you do spell interruption (personally I would) then it allows for interruption during the "casting", starting at the die roll, ending just before the spell goes off.
Ex. A casting of Fireball would be d6+3. If the player rolled a 4, the spell could be interrupted on a 4, 5, or 6. On 7, the spell is done and cast.