i was expending my knowledge about PAgP and LACP. It is known that Etherchannel is load-balancing. Is the LACP operation somehow changes this concept? I heard it does - by Choosing one line at a time (NOT load-balancing among the several lines...).
It depends on your outlook as to what Load Balancing is. EtherChannel load balances by MAC address (source or destination, selectable). So if you have just one conversation going across an EtherChannel you'll see one link carrying all the traffic and the other(s) idle. Add a second conversation and they'll use a link each. Put twenty on there and they are effectively shared out across the available links