Is it okay to uninstall the old versions of iWork/iLife after their respective upgrades that come with OSX Mavericks? I noticed after upgrading to OSX Mavericks that shiny, new versions of many iWork and iLife apps had appeared. Yet, the old versions remained installed. All the new versions seem capable of opening (and in the case of iPhoto, upgrading) old version ('09, etc) documents/libraries. They also seem capable of saving in these older formats.

Is there any reason to keep them? Or should I simply drag the old versions to the trash?

If uninstalling is the right choice, is there anything that needs to be done other than dragging to the trash?

Is it possible to remove the old versions, but retain the templates and other data specific to the old versions? The new templates are stellar, but being able to keep the old ones (e.g., in Pages) would be a nice bonus–double the templates.

Lastly, is there any impact on iCloud in doing so?

Any other thoughts between the versions, and keeping vs/upgrading? I have Time Machine backups, anyway, so I can always go back (presumably) and restore them should I need the old versions in the future.

Thanks!
You can uninstall them if you like. Apple leaves them behind so you can compare the feature sets and UI redesign to see if you want to use the new apps or retain the old ones. I personally dislike the new design, as it is too simplified and was missing some key features, at least in Keynote, which I use the most.

Remember, though, that whenever you click on an iLife document, it will always open in the new app. If you set the default app on a document to the old iWork app in a Get-Info window, Finder will soon change it back! Even worse, Software Update will pop up a daily asking to upgrade to the the iWork apps, with no way to turn this notice off.

Insidious nonsense.