Those all look great to me, with these exceptions:
A "slap up dinner" is a great dinner -- wonderful food and cooking. It refers to excellence rather than amount.
"veer" means more than "change." It suggests a diversion in the direction of your progress, being sent in another direction, to go off the path.
I don't know what "screaming eagles" means, but I think the gist of the passage is not that he gave speeches, but that his own thoughts were about military affairs, so as a consequence he talked about it in conversations.
"Taking someone for a ride" means "putting them on" -- fooling or deceiving them in US slang. I don't know what "giving someone a ride" means -- it's British slang.