1) When mining LTC I think the speed on the mining speed incorrectly shows MH/S instead of kH/s.
Edit: I am not too sure about 1)
I haven't heard of this bug, since it's strictly a numerical algorithm that gets applied to all hashrates regardless of coin type. It *might* be that you had selected a Bitcoin pool perhaps by mistake? I could be wrong though, please let me know if you've confirmed it and/or can repeat it.
2) The preferences screen is still blank after entering the Bitcoin address.
Are you using the latest version of Asteroid? I added a fix for that bug but it may not have caught it. I'm guessing the API reply from blockchain.info is giving it a hard time. I'll add some error-checking at the same time as I implement this same functionality for Litecoin addresses (in the upcoming version of Asteroid).
3) Once the miner is stopped I cannot start it again. I have to qui the program and launch it again.
Thanks, I'll investigate. If/when you can send in a feedback report (go under the "Asteroid" menu and go to "Send Feedback") with a line or two about what is happening, I'll have the relevant log files as well that Asteroid generates that may help me more quickly troubleshoot your specific setup (and implement a fix for everyone if possible).
4) When mining Litecoins there's an issue with the notification message in the dock. Think it says mis....lue or something like that.
Yes, this bug has been reported, and thanks for doing so as well. It's actually trying to say "missing value", which is an error that is coming from the litecoin hashrates not being parsed properly. It's on my list for fixing in the next version.
Keep it going. It really has potential.
Thanks!