Guest Briano1066, all-caps is shouting in internet parliance. While I am sure that you have great enthusiasm for your subject, you won't find many adherents to your point of view if you yell at us.
At anny event, the Celts favored the ax and sword over the club and carried oblong shields (Circa 280 BC). The round shields did not come into use until about the 5th century AD.
The shields were made of wood and covered with rawhide. If the warrior was wealthy, the rim might be bound with iron. It was common in all cultures that fought with sword and shield to beat upon the shield with the flat of the sword to cow the enemy. It was not a trait peculiar to the Celts.
Actually, the thing that made the Celts feared in battle was their utter disregard for death or injury once they had committed to battle. The only reason that Juilus Ceasar beat the Gauls was that they had no discipline in battle. Man for man, they could outfight the individual Roman but if their initial charge didn't break the lines, they were just as apt to leave the field and go home as not.
My own thoughts on the origins of the bodhran are not repeatable in print.

troll