anyway, we can't really tell that the DVD version performances are lipsynched/mimed/live because those DVDs are completely edited to make the singing sound perfect..it's really hard to recognize whether it's live or not..maybe during the encore parts where Ayu usually would shout at the audience and etc., that's not playback at all~
the only thing we could decide whether some songs are lipsynched/mimed/live are from TV version or some people who went to the concerts who can give us full details about Ayu's vocal~ so far, we all know that angel's song at PCDL0809 and Theme of the nation'03 at CDL0506 are definitely playback/lipsynch/mimed~ but for the rest of the songs in any ATs and CDLs.. it's totally hard to know~
oh yeah, one more thing, we also hardly know whether Ayu sang live or not because she never really does various kind of vocal improvisations except for the recent SURREAL-Evolution-SURREAL's performances, where she always did the "ahh..haa.. yeahh...yeahh..huuu..." with Peco and Princess.. (while teasing Yo-chan, haha lol), i think SURREAL-Evolution-SURREAL performances were not playback though.
Then, From what i could see from almost all her tours' DVDs, she hardly sang the songs differently from the CD.. so yea, that could make more sense that she could be using playback lots of time (oh well, i hope she's not like that because she seems very hardworking for the rehearsals if looking the off shot videos). If she sang most of the songs by adding some vocal improvisations in certain parts of the songs, I think that she can be assumed of not using any playback at all~
but, I don't think a perfectionist like Ayu, she would just using playback the whole time~ like someone said before, it would just risk her credibility of her singing.
i salute you guys who may give such contribution whether Ayu lipsynch in this song or not.. very detail

where i can't really point out which songs she does or not.. i only that she does for some songs~