Who exactly is Tobias Lloyd, and could he be Tom Williams?
He could be Tom Williams as much as you or I could be.
Well, even more so since he would have a reason to certify his own key.
True. But anyone could have done so and it wasn't at all necessary for Tom Williams to have that additional certification in order to sign his messages.
The fact that there is so much readily available information on Tobias Lloyd is in complete contrast with all the steps we can see 'Tom Williams' has taken to hide his identity.
It was always a long shot that Tobias might be someone who knew him.
Judging by Tom's use of i2p and the efforts to hide the whois information - he's not going to be found so easily.