Sprint HTC Hero :: Delete Entire String Of Text Messages In One Fell Swoop?

1. How can I delete an entire string of text messages in one fell swoop? I can delete them one at a time, but I just had to delete 44 text messages (an entire conversation between me and a friend) and I'd really like to know how to do this in bulk! (I am using Handcent SMS).

2. I can get the default ringtone to change, but I cannot figure out how to make each contact have its own ringtone. The manual says to go to the contact itself and then select "information" and then "ringtone," however, I cannot select these parts. They are grayed out. How to do this?!?!

3. I want the text alerts to only give off a sound, NOT a vibration and a sound. I went into the tools for Handcent and clicked the "vibrate only when device is set to vibrate mode" but it still vibrates. How can I make this work?

4. Is there a "help" section on the phone itself? Something I can search on the phone itself when I get stumped like this?