A front attack doesn't need so much superior speed. The closure speed is insane, so the key factor is a stable plane with heavy firepower.
A set up for attack may need some fuel. The more, the better.
A lower wingloading will give you both of those benefits, - carrying more as well as alt performance improving and ROC (if you work with the same weight).
Anyway, Knegel:
"they was able to bring a bomb into Hitlers HQ, but not a pistol??
Sounds like a real bad excuse to me."
Would you have had the brass to pull that one yourself? Do you think that you would have been quick enough in a room full of people, and possibly an armed guard behind you? Come on.....
It took balls to bring a bomb rather than a gun anyway, - a gun could be a forgivable careless thing, but a bomb was very absolute. And what I mentioned before, - Stauffenberg was supposed to survive. He was the person to fit as a "face".
As for Canaris, you seem to be confused. Here is something from Gripen:
"IMHO Canaris probably fought more effectively against Nazis than any other German. Schindler saved some people so did Canaris as well, the White rose did some leaflets."
I'll agree on that one. Canaris loved his country and got to discover the beastly nature of the regime he was working for. That was already in 1939, - long before "the final solution" and such things, even in Spain, the Nazis were excercizing mass executions. Poland was the beginning of those on a big scale, and both the LW and the SS were "applied" for the job. LW got targets to wipe out, SS were simply given a long leash.
Canaris saw that, tried to protest through official channels, and had to back with that. Even that was brave, and might have been the beginning of suspicions against him (main enemies Himmler and Heydrich), - but he was smart enough to duck them.
As an effective fighter against the Nazi regime I'd probably put him on top. And I'd call him a Hero, for he didn't jump from the ship, which he very much could have done. Nope, he carried on as he could with the hope that Germany could get through without being in ruins.
The real bandits that kept pumping "brave German soldiers" into the meatgrinder was after all, the hot beliving Nazi regime.
Guys like Rall will actually go as far as calling the Nazi regime "traitors to the people". As a pilot, finding out what was going on in the occupied countries as well as home in Germany (after the war), he described it as having been used and betrayed.
Here is something of interest for you Knegel, - something that emphasizes the regime's sense of realism as well as their grip on things to the very end.
Some days before Berlin fell, I think actually just right before Hitler took the "pop" solution, Schindler got a letter from Berlin. It was a complaint about the quality of his production, and with a threatening tone - he would have to quickly improve his quality of production or......
And BTW, Schindler was a Czech....well, Sudet? Not a German.
Now about the time:
"To try to kill Hitler in1944, when it was MUCH to late(for many Millions and germany)"
Not too late! Not at all!!! And exactly because of many Millons of lives AND Germany. Page up casualties, say from November 1944 to May 1945, - quite a bit I'd say. From all sides except the pacific. Think of all the damage done, the raizing of cities, and the absolute depletion of just about everything after the war.
1944 was a message of realizm. Any idiot could see that Germany was going to loose. (If not living in the Alps and reading only edited papers

) You had the Allies gaining foothold in France (with hopes of the war being over before Christmas) and the Russians going on at train-speed. . . .