(1) UA1(1000) is on conversation with UA2(1005) ?
yes this possible if you enable accounting you can view them in CDR
(2) UA1(1000) is on conversation with UA2(1005), then UA1 transfer to UA(1006)?
SER is a proxy, so to transfer to make conference you need to have thirdparty software to make them in 3way call.
still those records also you can view them in CDR as for as i know
ram