From a non-flying type,
1. Are "Bug-Settings" for V1 etc.. still (in this case A343) manually set prior to departure, or does the FMS handle all these data calculations and settings?
2. "IF" a rotation was commanded prior to v(rotate), does the deflection of ailerons increase drag and thus increase the length of runway required to achieve flying speed?
This is not an indication of what I think may/may not have happened, just a curious mind.
Invictus, I'm not "qualified" to answer your question, but this is how I understand it. (I'm sure I'll get corrected if I'm wrong!)
The V1 bug settings are handled by the FMS (FMGC in the Airbus). The figures are derived are from crew input however, as with any computer system (Sh!t in - Sh!t out).
The crew enter their weights (operating empty weight, fuel weights, and the current centre of gravity), plus the desired flap settings for takeoff and the current wind/runway conditions and pressure alititude. The FMS will then auto generate a trim setting and auto-populate the VSpeed fields, as well as produce an expected thrust setting needed.
It is however the resposibility of the crew to check these speeds against the various takeoff perfomance tables, and adjust taking into account all the variables such as wether engine de-ice is needed, runway slope, headwind/tailwind, pressure altitude, temerature, and reported surface braking action condition, among other things.
To answer question 2: If rotation is commanded prior to VR, (you mention AILERON defelction, I presume you mean ELEVATOR deflection?) then yes, this deflection will increase the drag and thus the runway length needed.
Some operators recommend that to counter the "nose-up" effect of setting takeoff thrust, aplly half-forward stick deflection until 80 knots, then gradually release until at 100kts. For crosswind takeoffs applying rudder and aileron deflection during the takeoff roll to maintain the runway centerline, the action of the spoilerons being partially extended on one wing can greatly increase the drag on that side of the aircraft, leading to the aircraft turning into the wind. For that reason it is not recommended to use excessive amounts of sideways stick deflection during the takeoff roll. If you do, you must centre the sidestick during rotation so you get airborne with zero roll rate demand. After that you are supposed to follow the SRS pitch command bar (a bit like the flight director).