So what? The Mosquoito only carried 458 gallons and had a far better range than any of those. The P-51D only carried 186 gallons and it flew further than any of them. Part of the reason was a much higher cruise speed! You analysis here is crude, war isn't so simple - aeronautics aren't so simple..
Mosquito carried 646 US gallons and no the Mustang with 186 gallons of fuel did not fly further than the bombers. A Mustang with 160 gallons (allow something for warm up and take-off) could fly around 890 miles at 15,000ft at 290mph true. (no combat no reserve.)
A B-25C/D with 900 gallons (allowing 70 gallons for warm up and take off, neither plane needs quite that much) at 15,000ft can fly a mere 660 miles at 280mph true but that is at max continuous power which would never happen. Backing the plane down to an economical 247mph true the range jumps to 1110 miles (no combat, no reserves) You can get a B-25 to fly over 1500 miles while carrying 3000lbs using the wing tanks alone if you slow down enough.
You are quite right, war is not simple and aeronautics isn't so simple. But comparing the most aerodynamic piston engine fighter of WW II to not particularly aerodynamic radial engine bombers doesn't tell us much either does it?
More to the point, Hurricanes were doing most of the tactical bombing in the Med and the Pe 2 out-ranged those significantly.
Sort of is the point isn't it? Are you going to replace the Hurricanes with PE-2s or replace the A-20s and B-25s?
The Hurricanes were better strafers than the PE-2 and while the PE-2 carried more bombs (2-3 times) they required 3 times the aircrew, twice the fuel, twice the maintenance time for the engines.
The PE-2s needed less fuel than the A-20 and B-25 and less aircrew than the B-25 but it wasn't any better at strafing. Bomb load for most of 1942-43 was similar to the A-20 but you need 3 PE-2s to equal 2 B-25s at best. at worst it is closer to 3 to 1.
The PE-2 doesn't have the range or bomb load to really justify it's logistical footprint.
Well speed is a factor. It's not the only factor, but it's a factor. I suspect speed is the main reason why the Pe 2 had a much lower loss rate than an A-20 in Soviet use (or an Il2)
According to this, the rate of missions per loss was:
Su-2 80
Pe-2 54
IL-2 (two seat) 26
A-20 19
IL-2 (single seat) 13
(source)
https://www.worldcat.org/title/soviet-combat-aircraft-of-the-second-world-war/oclc/40494691
The figures could stand closer examination or perhaps expansion?
The figure for the SU-2 is for the 270th bomber regiment operating during the Stalingrad defensive operations in 1942. Aug 42 to Feb 43? Dates not given in book cited. there were only 889 SU-2/4s built before production stopped in March of 42. One wonders if the loss rate was truly that low in general and not for a small quantity of planes why production was discontinued?
Likewise the loss rate for the A-20 is for the 221th bomber regiment (or division)? using early models of the A-20. Timing is not easy to sort out. for instance
we have "By the end of July, the 221st's crews had flown 876 sorties, and claimed the destruction of 171 tanks and 617 trucks and automobiles (along with other important targets). However, during this time, the 221st suffered heavy losses, with 46 of their Havocs shot down in the same time period."
However the Russians were getting a mix of A-20Bs and A-20Cs at this time and the A-20Bs had no (or little) armor and did not have self-sealing fuel tanks. The A-20Cs did. I think we can all agree that a force of planes with all self-sealing tanks would have a lower loss rate. Also under 900 missions might not be enough to get a really good statistical base to work from?
I would also note that the same source claims that the PE-2s loss rate hit that number of 54 sorties per loss
after the upper rear gun was changed from a single had operated 7.62 machine gun to a single hand operated 12.7mm machine gun. Before the change they had a loss rate of one plane per 20 sorties. Those are the numbers but do we really believe such a small change in armament could make that big a difference? The slower IL-2 didn't get that big a difference going from
no gun at all (or even some body in back seat shouting a warning) to the same 12.7mm machine gun the PE-2 used.
Later A-20s replaced the twin .30 cal guns (compared to the single 7.62/.30cal in the early PE-2s) with a hand aimed .50 cal. SHould we assume that they also then achieved a loss rate 2 1/2 times lower than the older Bombers?
So given that the A-20 was a successful "light" bomber for the Desert Air Force in 1942 and 1943, that they had similar range and bomb loads, and given that the Pe-2 was (as a dive bomber) more accurate, and based on the above statistics - could survive almost three times as many missions in a row before being shot down. And it could carry rockets!... I think it's a safe bet that the Pe-2 would have been pretty useful in the Med.
Answered above, but please note the A-20Gs were coming into service at the end of 1943. if a single hand aimed 12.7mm/50cal can almost triple the survival rate what do a pair of such guns in a power turret do?
That is certainly one way to look at it, but I don't think it's the only way. You did a good job of articulating the essence of our disagreement though. "Bomb Truck" is basically how the US approached heavy bomber missions in WW2 and in the Korean War and Vietnam, with limited and diminishing effectiveness. But it's not just about tonnage and range - to me it is a very simplistic way to evaluate a bomber.
Range and bomb load matter, of course. But accuracy, speed, survivability, performance, and versatility also matter. There is more than one kind of bombing mission, there is more than one kind of target. There is more than one type of threat.
And more than one way to accomplish a mission.
Bomb load and range are not the only way to evaluate a bomber but they should be the basis or start of such an evaluation. Bringing in the later wars just confusing things as more and more the overriding consideration was the reduction in casualties of the bomber crews and the high command (and politicians) were much more willing to trade massive losses in effectiveness for few casualties for political reasons.
Versatility does matter but it can also be overstated. For example the P-38 fighter was versatile, but it's usefulness as a recon plane (and hundreds were built without guns and served as photo recon planes in all theaters) or as a substitute bomber (bomb under one wing drop tank under the other or the drop snoot experiment) have little bearing on it's usefulness as a
fighter, however useful it may have been as an airframe/aircraft in general.
A lot of the desert war bombing was from low and not medium altitude with somewhat greater accuracy so the difference between the "level" dive bombers and the dive bombers should not be quite as great. I would note that all air forces over claimed considerably on ground targets, see above quote for the A-20 in Russian service, 171 tanks? It is quite possible that single German panzer division didn't even have 171 operable tanks in the summer of 1942.
You did mention "more than one kind of bombing mission, there is more than one kind of target." and while the PE-2 might be good at some it rather fails at others like attacking ports or flying from NA to Sicily or southern Italy.
I think the Pe-2 was
easier to fly (and more maneuverable than the others), maybe you are thinking of the B-26?

Pe-2 was qualified for acrobatics: loops, rolls, steep bank turns etc., according to that USAAF film you posted earlier, the A-20 wasn't rated for that. I know the B-26 wasn't!
do not confuse acrobatic ability with being easy to fly. The PE-2 had some rather nasty low speed characteristics. SOme of the Women pilots needed the assistance of the navigator/rear gunner helping to pull on the stick to get them off the ground at times. The wing section/airfoil while quite good for a dive bomber (little trim change needed over a large speed difference) stalled at about an 11 degree angle of attack and the stall was often sudden and asymmetrical.
The PE-2B of 1944 had a slightly larger wing of changed airfoil to improve take-off and landing performance and "lessened the tendency of the PE-2 to fall into a corkscrew at low speeds"