As to the timing, I've heard it came due to delaying the confirmation of Rod Rosenstein as Deputy Attorney General. What is with holding those confirmations out so long especially for someone like Rosenstein, who it is claimed has worked for Dems and Repubs and is respected by both. What that delay meant is looking at Comey, since it related to the ongoing and seemingly never-ending FBI probe into Russian connections to Trump and his people, had to wait for that confirmation, after Sessions had to recuse himself due to talking to Russians when he was a Senator and during the campaign. Doubtless from the time he was nominated, Rosenstein had been studying the matter.
It seems Rosenstein didn't approve of how Comey had acted as FBI director in taking power into his own hands, basically grandstanding (and he'd done it earlier in positions he'd held). I've read Comey kind of saw himself as a white knight which sounds noble but can be threatening also when the knight acts outside the law and consideres his motives to be above those of others.
Finding out the whole of this will doubtless take years to come out given our partisan divide today. When I listened to Democrats complain about the firing, they all had the same talking points and never answered the question of whether Comey had been a good Director and should he have been fired. It was all about the timing and that came down to scare talk of a kind of coup.
The other fear-mongering thing I've heard is the firing was to stop the FBI probe. This would indicate such people believe that is all being done by the Director. From what I can tell, it will not end FBI investigations into possible nefarious dealings by Trump or his people- nor stop Congress who is also investigating. It won't end leaks, which I'm sure there'll be plenty.
One thing that surprised me, besides the suddenness, was that there were those in DC scared of Comey and the power he wielded. That means they feared he'd use it in ways that went beyond the law-- as he did when he revealed all Hillary had done but then said can't indict her despite that not being his job to determine. While Republicans might've liked that when it was her, they'd not be thrilled by a Director who did it when it was their side...
Another kind of humorous aspect is how the Dems claim this was to stop him from testifying again. Seriously, like they couldn't ask Sally Yates questions or Comey now, who might just be eager to not only justify himself but nail Trump. Then one dem suggested they let Comey run the senate investigation.
Curious times indeed!
After that, Rosenstein said he didn't threaten to resign.
I think I'll follow a new rule for the rant-- only post an opinion after a week or two have passed to be sure the whole story is there... or is that long enough? lol