I've never had a paid account, so I can't answer that one directly, but I do know that you can choose to switch to basic account. I've done almost the same thing as you. I deleted all my posts except one explaining where I went, and switched to basic. I still keep an eye on my flist, since most of them flock, and post to my community, but that's it.
If you know the passwords, or know someone who knows the passwords to these journals, they can make you an Lj Book. It's very useful and includes comments as well.