As for you, 'Vic, I don't think Technician will work on Weather Ball during active weather - since the BP of WB is raised to 100. I may be wrong, of course, but don't think that the mechanics work like that. Besides, if that were the case, it would be way OP.
Actually, according to the PS! Damage calc, Technician does not apply to weather-boosted Weather Ball:
252 SpA Roserade Weather Ball (100 BP Fire) vs. 252 HP / 252 SpD Scolipede in Sun: 316-374 (97.5 - 115.4%) -- 87.5% chance to OHKO
252 SpA Technician Roserade Hidden Power Fire vs. 252 HP / 252 SpD Scolipede in Sun: 286-338 (88.2 - 104.3%) -- 31.3% chance to OHKO
Chlorophyll instead of Technician, would of been death. I was so disappointed when Roserade got Technician as a DW ability. :P
Works like Revenge/Avalanche then I guess. Technician applies unless the power-doubling effect kicks in. ie Technician Revenge has 90 if they don't hit you and 120 if they do.
That's good then, since Extrasenory would be a giant pain to breed (same difficulty as Selfdestruct Munchlax) and Technician Weather Ball is pointless, that means there's basically no reason to breed any extra Roserade. Just need to breed a Timid one / don't have to bother with Exeggcute / don't have to get DW.
Also that calc needs to add Electric Terrain / Grassy Terrain's multiplier to Electric / Grass moves, it's pretty much the only thing missing and I kinda wanted to play with its effects.
And since I forgot to specify earlier, I used Rock on Lilligant.