Everytime I log-in, my applications from my previous session always open in the first workspace. Is there a way for them to stay in the same desktop that they were in when they closed. Or, alternatively, is there a way to make certain applications open in a specific desktop (such as making thunderbird ALWAYS open in desktop 4)
I don’t use KDE, but I suspect that getting KDE to remember where programs should be started is not possible. I think that you other question about how to start them in specific windows is the way to go.
There is a app called “devilspie” which I’m about to look at, it allows you to start programs in specific Workspaces. Install it and have a look at /usr/share/doc/devilspie/examples/sample-config.xml, this might be the way forward.