Nice update, but Spangler almost certainly had nothing to do with the conspiracy. The only thing Spangler did in OTL to help Booth was hold Booth's horse just long enough to hand the job off to another unwitting employee of Ford's Theatre. Also, considering OTL's actions, it does not seem credible that Powell could be subdued by only one man after a minor injury.
Spangler's "friendly" acts towards Booth will be sufficient to have him implicated in the conspiracy. The involvement of the "Baltimore Spy Ring", although more likely in TTL, is still going to be quite sketchy.
As someone with a nice round scar on my foot (it was a half inch wide spike rather than a bullet) let me confirm a small child could have knocked me over in the seconds after it occurred. Foot injuries, I am told, are among the most painful. Also there were at least 6 men in the room - William Seward, Frederick Seward, Lord Lyons, Colonel George Bell (British Army - on leave touring America. Included by Lyons as he served with Leventhorpe in Canada), and two legal counsel who I haven't identified yet. Bell was a great lump of an Ulsterman and therefore he almost certainly assisted the younger Seward in subduing Powell.
Custer is moving up in the world.
Hooker/Custer ticket in the future?
That would be the pimpingest ticket in American history.
The Hooker ticket will have a more controversial VP on it. Custer's military career isn't over, but I suspect he will run for public office eventually...
I thought "How do I give Lincoln a retirement he can enjoy?". Perhaps I am an unpleasant man. Perhaps I have read too much into the inevitability of Mrs. Lincoln's illness. However it seems the best way to give Lincoln a bit of peace.
It will be interesting to capture the feelings of Confederate officers at the attack on a God-fearing, Southern woman sympathetic to the cause of the south. Ben Hardin Helm in particular.