1MUNK3, I agree with most of those, however some I would put in the same genre as Flogging Molly and Real McKenzies. The Exploited, Sedition, are definitely an Oi punk band, and don't play folk rock at all. Oi Polloi is interesting in that they sing in Gaelic, but their music isn't especially Celtic sounding, and they have some lyrics which I don't really care for. The Dubliners and the Clancy Brothers are exclusively folk bands (except for when The Dubliners perform with The Pogues). The Levellers are more Celtic rock than Celtic punk, and Runrig is like stadium rock, although I do like their version of Loch Lomond with the Tartan Army).

Some others I'd like to suggest though:
Charm City Saints
Neck
Siobhan
Sled
The Prodigals
Orthodox Celts
Fiddler's Green