The super hornet is angled out for separation issues (ie dropping or punching stuff off so it doesn’t come back and bump into you). So not necessary for a model

The down angle of tanks on the FS is so they are aligned with the relative wind for normal flight (ie compensate for angle of attack). Makes sense in a model for lowest drag. For tip tanks I would think same incidence as the wing but there are smarter people here

hope it helps!