Jon this thing of being called fickle and having your support questioned is obviously new to you mate but I shouldn't worry about it too much. it tends to used when people can't think of anything else to say, and you do get used to it after a bit. The next step on from not being a "real" fan is to be accused of Supporting Man Utd, or of "hating Rafa with a passion", but you probably won't get any of that I shouldn't think.
As for the other stuff don't worry about it.