Rather late, I guess, but I have a 'pre-installation' script, called Gladstone, which you can run which does everything necessary to let 64-bit LMDE run 64-bit Oracle 11g Release 2. Run it on a shiny new LMDE installation, and all your kernel parameters, user accounts, directory structures and symbolic links are done for you. You just then launch the Oracle installer, click Ignore All when the Oracle installer complains that nearly everything is wrong, and then let it do its stuff regardless.
During the linking phase, there will be "error in invoking target of makefile..." errors. When the first one pops up, just double-click the "fix-lmde-linking-errors.sh" script which Gladstone will have written to your desktop. Once that second script has run, click the 'Retry' button in the Oracle installer and the thing will complete successfully without further incident.
My article describing Gladstone
maybe sets it in some context.
If you just want the script, that's available here.
And proof that it's readily do-able without having to resort to using Oracle XE is here.