I don't know about that Alec

The thief and wizard characters don't need to be present. M&B isn't very magical so the elf is a good balance, but the wizard would be too much.
1)How long does it take to make a whole new quest?
2) How long would it take to "reformat" the first 2 quests into the 3/4 single player style?
I don't track the time, but I can estimate.
Considering I'm always testing new features (magic, upgrade system, etc.) as I'm implementing levels and testing them, it's hard to judge.
...let's see there's level layout, item modeling and texturing in Wings, into BRFEdit, into module system, checking graphic errors, putting in props, door-spawns,etc...playing the levels myself, testing difficulty...loading M&B up anew for every fix...
Probably takes 15-20 hours...
Reformat levels 1&2 and fit them into the module system, etc.? Probably 5 hours or so.