All it would do, making firebomb and RW usable on the move is give engi's and magus some mobility currently and even on official servers all engi's could do while kiting is use dots and hip shot every 10 secs. Magus i never played but im guessing its the same so testing it wouldnt really mean much, its obvious how it would work out.
Thing is engi and magus were designed to be the stationary rdps, even without a range snare they still do pretty dam well as is and in t4 they have access to a range kb which i guess u cud argue makes up for no range snare and fits more inline with the stationary rdps role.
I still think it would be a positive change to engi and magus given the overall feeling of them being the gimped rdps, saying that they will still be more then fine left as is

Morfee - Shaman / Mynnos - Kotbs / Grubod - Black Orc / Snubz - Squig Herder