Haven't ever tried it as I don't date, but my guess is that I'd be worried. Someone saying they love you early in a relationship when you consider it too early usually either means that they're feeling they have to say it or they are complete and utterly obsessed with you - and not in a good way.
I find it hard to believe them, even if they believe it. It makes me feel uncomfortable if someone is not moving at a similar speed to the one that I am traveling at. I don't like the idea of someone thinking he loves me when it is too early for him to really know me well. That usually means it isn't love, but something else like infatuation. There are some people who like the idea of being in love or loving so much that they will rush or imagine the feelings.
It worries me. I hate when that happens. It always means that they are emotionally not right - either clingy, desperate, socially stupid, etc.
Worries me A LOT. Actions, not words.
Yes, but saying they are IN-love is a little scary. ;}