(a) I doubt, but I don't really have an answer so I'll skip
(b) I think VPNing out from Tor and ride a botnet will make you pretty much untraceable. It would be really hard to find you because of both technological and legislational barriers (where is your VPN? and the bots? Qatar? Good luck). Following the money trail would be a more reasonable way but still electronic currencies are hard to trace (LibertyReserve, and so on) due to foreign legislations and in the end they could always have funded themselves from stolen credit cards (a quick search on pastebin and you can buy some for yourself fresh from skimmers). And not talking about bitcoin.
(c) I don't think LulzSec are skiddies. A bunch of skiddies would be in jail right now.
Is every website really this vulnerable to DDoS?
The kind of infrastructure you need to defend against humungous DDOS attacks does not come cheaply, whether bought or outsourced.