I try my best.
The remarks of @RunaDacino should help you a lot.
My additional feedback:
#1:
You simply play the wrong mode.
Air AB has significant advantages regarding gaining crew XP - but Air RB generates way more RP. I show you an example later, but if you use the search function you will find countless threads dealing with this topic.
What most people realize too late is that the majority of RP gains in Air RB result from staying alive and doing something useful whilst playing.
I played just for fun 5 matches in my B-18 B (with a talisman) - gaining 39.000 RP in total within a range of 5.000 - 15.000 RP per match - without dying and a few bombs dropped and a few guys killed. Even considering that i gained roughly 16k RP from the new research bonus, the RP income without a talisman would have been ~ 11.000-12.000 RP…
#2:
This is definitively not true for domestic prop fighter aircraft - the best prop fighter in the Swedish TT is from Finland: the Pyoerremski.
The Saab props are basically slower 190s (J-22s) or actually extremely overtiered (J/A 21s) - a result of the usually higher skill level of non-Big 3 pilots and insanely powerful Akan 13.2 mm cannons.
The B-18B is an outstanding bomber - more later. The T-18Bs are actually postwar strike aircraft but as Sweden is the darling of Gaijin they have a bomber spawn and murder enemy bombers…
The J26 David premium benfits from the low skill floor from US pilots and could be easily 4.3 instead of 3.7 in Air RB.
#3:
I saw you have the B-18B - correct flown a pain to kill and steady income source. I received 4 talismans from gaijin and one of them was for it. The 2 x 600 kg M 50 bombs are able to kill 2 bases on most newer maps which generates around 870 point mission score and ~ 700 rp.
The best match of my 5 attempts:
Gaijin Entertainment - Single Sign On
The game was quite nice - it shows the combination of luck (strafing two enemies and getting a gunner kill on a Pe-8), the dogfight capabilities of the plane vs a Bf 109 F-4 with a massive energy advantage (he had zero chance in a turnfight), my potato aim (partly excuse by using a HOTAS) and finally the rather high durability of the airframe in addition to the very good flight performance.
So it might be worth your time.
#4:
As i use a HOTAS i do not perform any head-ons due to the lack of accuracy vs mouse aim pilots - i fly either planes able to play energy or well turning aircraft.
But i fully agree with @RunaDacino that a head-on is actually a noob move as any skilled pilot knows how to dodge and you risk a lucky hit. The only exception: You are forced to take is as you are too low and/or too slow to dodge and out-turn / out-energy your opponent.
I guess i have max 20 head-on kills out of my 14k player kills on this account…
Hope this helps a bit. Have a good one!