This is a good diversion. You have done Perf A - hence you have a start to a reasonable grasp of the subject - such discussions on PPRuNe are a useful vehicle to knock off the rough edges.
For the majority of the younger pilot set, I suspect that performance doesn't go much past learning how to look up the RTOW tables on the flightdeck whilst on the ramp. Certainly, if that not be the case, then a lot of folk were asleep during their performance lectures. For the airline with which I started out, the Ops Engineers did all these lectures and the folk got quite a bit of over and above information .. albeit that many never quite got their heads around the nitty gritty.
If you don't have enough TODA pavement ....
TODA generally comprises the whole runway PLUS the clearway. Clearway usually is not pavement and, most definitely, is NOT for mixing with heavy aircraft bogies. It is not a case of having enough TODA - rather, you limit the TOW such that the TODR ≤ TODA. If you don't do this you are outside the AFM rule book requirements.
then you continue rolling on the clearway
I really hope that folk don't want to do this - against the rules and pretty foolhardy .. you MUST plan the numbers on the basis of being airborne some distance PRIOR to the end of the declared TORA.
then rotate and lift off
liftoff MUST occur not further along than that point in the declared TORA which will constrain the first half of the airborne distance to screen to be located over the TORA ie you MUST always be airborne BEFORE the end of TORA - the runway sealed bit.
all your take off flare distance will have been over the clearway which is a no-no (1/2 flare dist limit).
No - you are missing the important distinction - only a portion of the flare will be located over clearway and then only if you are running with an unbalanced takeoff schedule - TORA doesn't extend into the clearway bit. For a balanced field approach to the problem, clearway is irrelevant and doesn't come into the discussion at all.
However, please do continue the discussion - the aim is to air these sorts of things especially for the benefit of the newchums who often don't get any of this stuff in their training.