Red Skull wanted to blow up most of Earth's major cities (including Berlin, his OWN capital) just to prove his own godhood. Sorry, but I fail to see how he "wasn't evil enough." Also, Red Skulls motives vary, he didn't seem to interested in "promoting pain an suffering" in Brubaker's run. He just wanted to take over the US, simple as that.
Except that could have been step one in promoting a dictatorship that would eventually serve at his cruel and sadistic impulses, I don't think Red Skull lost his cruelty under Brubaker's pen, considering how he treated his own daughter, I actually think Red Skull is more consistently written then Doom and Magneto are.
Movie Red Skull lacked the more personal acts of cruelty that comic book Red Skull had. In the comics, Red Skull likes to inflict cruelties on sorts of people, his daughter, his girl friend and random people who did nothing to him. Red Skull doesn't act cruel because it gains him power, he acts cruel, because he likes being cruel. Comic Book Red skull isn't just power mad, he will do cruel and sadistic things, because he enjoys them. That is what movie Red Skull is missing.
What you're thinking of is an anachronism (something from one era or time period being put in another era or time period) and I think that's part of what makes old school Cap awesome. It's like seeing a space-ship show up during WWII. By your logic the cosmic cube should not have even been a plot device since it ruins the super realistic WWII aesthetics. The whole point is it's this very real war that takes a very strange turn. It's essentially the first real taste of The Avengers where the real world is invaded by aliens and gods. I like that about it. Bullets flying everywhere and then suddenly "Holy ****! It's a robot!" (I'll be honest. Kind of hoping the giant robot will show up in this like it did at the end of the Winter Soldier storyline in the comics).
Also I don't believe Superman IV was based on any comics. I feel those movies, all of them, started making up powers and events considered silly even by comic book standards (but then again, silver age DC was already pretty ridiculous).
It didn't feel awesome to me, it felt like censorship and hand holding and really Golden age Captain America comics had Nazis and real guns, so I don't see how laser guns are more true to comics. This is why I didn't like the 90s Spider-Man, it was so censored and water down, that it affected my enjoyment of the show and really the movie felt like the censorship was affecting my enjoyment of it.
I think I would have preferred one or two over the top things, like a few super soldiers and Red Skull having a doomsday device and have the rest of the movie be a straight WWII story, within PG-13 bounds of course. The laser guns felt really out of place and ruined any feeling that this was a real period piece. I like laser guns in certain settings and contexts, WWII is not a context in which I would enjoy laser guns. Again just because a film is based on a comic book doesn't mean I have like everything within the movie and accept it just because it is a comic book movie, especially since in the Captain America comics, Cap fought real Nazis with real guns in WWII.
Again if the next Captain America movie is supposed to be a political thriller, would laser guns fit that tone and context?