Play what you believe in. Or play what is safe. Or play what you know. If you are neutral on the question of Irish independence, there's no reason to perform Irish rebel songs unless you want to introduce them as bits of past history (assuming you know the history of the "Black and Tans"). I have a friend in Michigan who actually makes a decent living as an Irish folksinger who refuses to do anything political. Be ready to defend what you perform, if you choose the political route. It's hard, at best, to claim a neutral stance if you are lambasting the British in every other song. There are a number of Brits and Irish who have had and do have very firm opinions about a number of U.S.A. issues (civil rights, Vietnam, etc.) Do they have a right to voice these opinions in song? As far as I'm concerned, they do. By the same token, I will do the same. As with so many other questions, you have to do what is right for you. The tricky part, of course, is making an informed decision on what that is.