Hey Jowe, surprised nobody's answered this yet!
As far as I know, it's your model, once the paint is dry you can sand out anything you want!
The old rattle cans save you mixing paint to proper ratios, but they lack control, and as you've found out they usually give you more paint than you need! Yes, I'd sand out the runs, and to be honest I'd sand the whole thing slightly. Get rid of the runs with a fairly coarse sanding stick/paper, then do the whole thing with a fine grit. Then give it as light a coat as you can, even if it looks like you haven't given your Typhoon full coverage - you're much better off going with 2 or three light coats than one thick one (that will likely run!)
Everyone (myself included) will tell you that an airbrush is the way to go, but there is no harm in starting out with the spray cans.
Hope this helps,
Vance