I dont know if this has been discussed in the past but, how about instead of a magical ring and what have you,it would be more of a perk acquired say in alteration,while in flight mode, if it can be enabled as well, be able to fight, but the downside is while engaged in flight mode all magicka and stamina requirements are increased diminishing almost to nil on every step up of the perk and increasing flight speed at the same time. Also, instead of having a hot key while this active effect is one it wouldnt really be a spell but an active effect like a warriorstone or some kind of permanent enchantment, it would then be activated by double tapping the jump key whilst flying so then u would go in the modified swim mode. Finall,y the way i think flying in skyrim as far as the PC s concerned would be, to use the same run time animation as swimming, but be made to look somewhere else for the animation sequence.It would use the same animation loop it uses now,but ina custom folder or animation sequence, that would resemble super heroic flight with a fist extended forward another backward or both fists forward or both hands open forward hands facing up. Something like this I suppose: