For many ships....the Butler/later Nixon air extractor can suitably vent a cockpit and limit high pressure air not through the wing leaks......
Yes.....various gap seals on wing control surfaces help.
Yes...."boots" of some sort where the wing to fuselage joint is helps.
Yes....many older "glass" ships had shrinkage on spars and dive brake caps....... profiling can help....best profiling won't fix a poor airfoil, but can make a poor airfoil work at max design. Basically, make it work as designed....usually stay away from bugs and rain.....