Re: I love U.
No, I would never say it without meaning it, even when I mean it, I'd think a lot before saying it, because the circumstances, time, people, attitudes, people...everything changes! So I wouldn't like to be called a fickle minded person by saying it once and denying it at another time...so I'll use these words only when I'm absolutely sure that my feeling won't change with the passage of time...and also when I'm sure that the other person loves me too! :)
And no, I wouldn't use this expression only for the sake of the other person's feelings.