You mean a 50HP difference is a significant difference?
It is a difference, i.e. it is not the "SAME". And since we're talking about twins, it's a 100 hp difference.
The 219 was underpowered.
No it wasn't. It had roughly the same power loading as the P-47D. I'm sure climb and acceleration would be similar too. I've never heard the P-47 being described as "underpowered".
...that it has more firepower than the 410 (arguable in practice).
It
has more firepower. There's no arguing the numbers.
You argue that it's comparable to the 38 in maneuverability...
No, I've never argued that. I said it had a comparable wing loading to the P-38, in context to Wmaker's claim that the He 219 had "rather heavy wing loading".
...that it's 400mph-class while the 410 isn't (arguable again, only a dozen MPH difference and huge heft)...
Again, nothing to argue, just hard numbers. And it is more like two dozen (with a clean 410, no gondolas or protruding guns). Weight (heft) has little or no impact on top speed, and the weight difference with similar guns and fuel isn't that much.
SM guns don't mean any more for combat than rear guns on the Me110 do. Unless you can fire em from the cockpit and not from a gunner position (auto-pilot automatically toggles)...
They were fired by the pilot.
Even then, it's a practical firepower of only 2x108.
LOL That's the first time I've heard/read anyone say "only" two MK 108's! Two 108's will rip any bomber apart with a one second burst, and with the Jazz Music it can be done quite a lot safer compared to a conventional attack.
...and from up close it's really a dodgy factor since the 219 is big and slow...
The 219 is faster than the 410, so what does that make the 410? Big and slower?

What's the significance of 4x108 when you're bigger and slower than a mossie?
Bigger yes, slower no. The 219 is faster than the Mosquito F.B VI (as modeled in AH). Why can't you get these simple facts straight?
The 110 demonstrates this easily.. 4x20 and 2x30, and how many of them do you see in AH dogfights?
I'm not sure what you're getting at, but I see plenty of 110's in dogfights, especially when I'm in one.

Anything the 219 does, the 410 can do as well or better.No?
No. With more guns, more weight and more speed the 219 is clearly the superior B&Z'er. That's what made the P-47 great, guns, speed and inertia. Not power loading or wing loading.
The big picture is that the 219 is dogmeat.
Against the top five most used MA fighters I'm fairly certain that both the 219 and 410 will be "dogmeat".