Spock says that the war was fought in a more primitive time with atomic weapons
Spock says that the weapons were primitive "by our standards." That's the same as saying that the atomic bombs dropped on Japan were primitive by today's standards - which is true.
There was nothing on ENT that contradicted the fact that all their weapons were primitive compared to TOS.
In a Mirror Darkly, Part II even goes so far as so flat out say so.
Also, who's to say that phase pistols and phase cannons - or for that matter phasers from TOS and beyond - aren't atomic based weapons. Again, they were just less refined and developed as the TOS versions.
ships so limited that they couldn't take prisoners
The NX-01 was a top of the line ship for Starfleet and it was only ever shown to be capable of holding two prisoners. Not much chance of holding multiple Romulan P.O.W.s there. Any other ship would probably have even less room for prisoners.
with no form of visual communication.
ENT never had Humans, Vulcans, Andorians, or Tellarites lay eyes on a Romulan. The one time there was communication, in
Minefield, it was only audio communication.
Spock doesn't say that there was no visual ship-to-ship communication whatsoever - just that there was none with the Romulans.
ENT went out of it's way to maintain continuity there.
Enterprise violates all of this. What say you guys?
No, I can't say it does. A lot of the criticisms directed at ENT on this regard seem to be, in my opinion, coming from a misreading of what Spock actually says.
1.) He doesn't say the war was fought with nuclear bombs like we have today - just that the weapons were primitive compared to what he was familiar with. 2.) He doesn't say that the ships didn't have brigs - just that they couldn't take on massive amounts of prisoners. 3.) He doesn't say the viewscreens didn't exist - just that nobody has seen a Romulan.
Now, I'll grant that fanon - not canon - had previously established that he said all these things and that the war was fought with nukes, no brigs, and no viewscreens. But that doesn't matter. There's nothing in canon to back up these criticisms.
That seems to be ENT's main problem - it stepped on the toes of previously established fanon tremendously.
But, IMO, fanon can be violated and it doesn't bother me at all.