Extensions are available they'll have to be ported to the new format https://github.com/SeleniumHQ/selenium-ide/wiki/Getting-Started-with-Plugins.
We do not have code export at the moment but are working on https://www.npmjs.com/package/selenium-side-runner.
Right click definitely works! make sure you are recording prior to using it.
And we are backwards compatible, just load the old scripts up.