HI TedStryker, you don't seem to need 3d advices as your model is very well done.
I like your portrait of the G3M, and the amount of details you have modelled.
The relatively high polycount for the turrets is "normal" and a good sign that the tris are put were they should be, in the parts that are more complex.
Good luck with that poly reduction!
About the wing fillets, if you want to take the advice, I'd recommend making the wing without the fillet, just straight as per the profile you use to extrude or model it, and then in a later step make the fillet as a separate part, to close the gap, like in real life.
You can use the side view to make a closed spline with the shape of the wing fillet and use it as guide to cut edges in your fuselage where the wing fillet should join with it.
Then from a top and bottom view cut the edges in the wing where the fillet joins the wing.
Extrude the spline that you made just straight some distance, and use the snap option to join the vertices of the wing fillet with those of the wing and fuselage.
Then you can add one or two loops along the fillet to give it some curvature and put it in "shape"
Finally (as an option) once you join together wing fillet with the fuselage and the wing, you can delete (or not), the inner part of the wing that is not seen.
Also probably will look more natural when separate smoothing groups are used on it in this way, as it is really a different surface than the wing and fuselage.
I swear that is simpler to make than it may looks... ???
Anyway, I'll enjoy to see your next screenshots, congrats on that excellent work so far.