1) In LJ client (Win32), View > Options - you should add a checkbox feature, where you can add/remove the auto-load of LJ. Saves my time diving into the Start menu to delete it...
2) Under the View menu, I see two different type - Mini Mode and Journal Mode. How about adding another one, maybe something like "Full Journal", where you will have a subject line, the message body and the Post Option on the bottom, after the message body. I found that I was being lazy and I couldn't be bothered to click on the "Posting Option" button to change the mood settings and other things.
I'll add more if I can think of any more.
Any comments/suggestions are welcome for this wishlist above.
Another one... when you reply to someone's message, there's no way for you to edit it. How about adding a feature, where one can edit their replies? I often replies to someone's message, only to find that I made a typo or something. To fix it, I either have to delete it and re-post another message or live with it.