would it be possible to mute or default sounds for friend logging in/out of the messenger OR have the settings you set save indefinitely (preferred option realistically)?

IM sent/received is already off by default (or its the only change that gets actually saved, its been so long i dont remember).

This has now been fixed, you can now properly save your sound notification settings. If you already have a tab with chat open, you will need to refresh to get the update.