According to one of the previous development updates they have placed a dedicated AI guy in the team, he's the one currently redoing the radio commands menu. AI improvements will be his next project once all the radio commands are working.
As for bombers exhibiting fighter-like behaviour, if you are flying missions from the QMB it depends on the group they belong to. If the stock mission pits you against Spitfires and you change them to Sunderlands, they keep the AI properties of the original mission (seems like the QMB is a "change some parameters of the stock mission" type of overlay and only the type of aircraft changes, but the rest of the group's properties don't) and that's why they react crazy.
On the other hand, some of the RAF bombers and even heavies (Sunderland included, if you've read that well known combat report of the fight between a Sunderland and a flight of Ju88s) were not too shabby in terms of maneuverability and there were standardized evasive maneuvers for the pilots to follow that don't exactly correspond to the long-standing simmer's convention of "bombers always fly straight and level".
The most "famous" one was the so called corkscrew which, if i'm not mistaken is like spiral diving the bomber
This was a direct consequence of the different doctrine employed by RAF bomber command, where most of the time the bombers would fly at night and thus not in formation (to minimize risk of collisions), so they had to rely on maneuvering to throw off attackers because they lacked the formation's mutually protective gunner coverage. This would be the same for solo operating aircraft like long range flying boats patrolling for U-boats and so on.