Just sharing here how I deleted all content from my 30k+ karma account. It's an easy to use, open source, and private way to do it, check out PowerDeleteSuite.
No need to install anything, just bookmark the JS script and run it. This tool was posted here almost 3 weeks ago, but I thought of enforcing it, with the great blackout approaching. The best thing about PDS is that it should remain working since it doesn't use the API.
PDS is able to export your comments, but to export saved items you might want to check Rexport - this one uses the API however, so maybe run it in within the next hours.
I hate having to do this, but Reddit doesn't deserve the community it has.
I used it yesterday to overwrite everything, twice, before I deleted every comment more than a week old.
It was very freeing!