I would recommend making it easier for planes to fold up/fall apart though. I'm sure it must have happened a lot more in reality than it does in the sim, especially given the number of rounds I put into some planes and the amount of bits that come off.
No question. Combat reports are rife with descriptions of planes coming apart. Damage them enough and if not destroyed outright, Gs and relative wind did the rest. Still, I do not know if this happened more than is reflected in the sim (I've never seen it but I haven't seen many kills at all), but planes certainly did come apart in gunfire.
Here are excerpts from MvRichthofen's (translated) combat reports that describe attack-related structural compromise (I'm using these because they happen to be right next to me; if I spent a couple more minutes I could produce many British examples, too):
(#21) ...I shot at the falling plane until the left part of the wings came off...
(#22) ...After the 400th shot plane lost a wing whilst making a curve...
(#24) ...The wings of the plane I attacked came off...
(#26) ...In a favourable moment I attacked the B.E. machine, and after 200 shots the body of the machine broke in half....
(#27) ...In my machine-gun fire the plane lost its open work fuselage...
(#28) ...After a short fight my opponent's plane lost both wings and fell...
(#39) ...After a very few shots the plane broke to pieces and fell near Vimy ...
(#47) ...I observed an artillery flyer, approached him unnoticed, and shot at him from closest range, until his left wing came off. The machine broke to pieces and fell down near Mericourt...
(#49) ...The plane I had singled out broke to pieces while curving and dashed, burning, into the swamp near Lecluse...
(#51) ...After a short fight my adversary's plane lost its wings...
(#56) ...We spotted an enemy artillery flyer whose wings broke off in my machine-gun fire...
(#67) ...both decks [wings] were severed from the English plane by my bullets...
(#73) ...I shot at the plane until it broke to pieces...
(#77) ...I shot at an enemy plane some 200 meters off. After I had discharged 100 shots the enemy plane broke to parts...
14 airplanes--18% of his credited victories--broke up during his gunfire. Others broke up during their "dash" to the ground, but I only included those that fell apart during the attack.