The kame is still more powerful than the FF, and it takes some time to charge, but its far worth it... very nice splash in high level games... as for the galit gun, later it becomes usless, but then you should be SSJ... and who in thier right mind would try to block a kamehameha with the friggin gallit gun? either dodge it like its a heatseaker or fire a big bang into it and do a power dive (Or just turn your fly off so you smash into the ground)
I pretty much only use veggeta, so i know his moves well... it IS possible to push back a kame with final flash, but its safer to throw a bigbang ball into it and run, since it will slow it down enough to get away, and he's stuck there in a power struggle, giving you a change to put your boot in his head.
And as for you, cold steel, there is a reason its called *final* flash...