I have yet to find a good way to keep track of replies to my forum posts (or updates for that matter). It's not important necessarily for the game, but for the community.
I find it difficult to play and chat at the same time, so I usually have to choose one or the other. I think that's why so many people are silent when they play. It's too hard to nibble, type, pet, type, water, type, harvest, type, mine, type, squeeze, type, milk, etc. and that would be me trying to say a couple sentences to someone while we're both walking on the same street. Very annoying and breaks up the game play too much.
@TRB4: If only pressing the enter key with nothing in range of an action opened up a small chat window that I could type in. Because you're right, it IS very difficult to move back and forth from the game screen to the chat screen, esp when you're using WASD to move around.