1. During setup of the account, it will ask you where to save the PST file, so it's good.
2. I keep an annual storage of the current PST files.
3. I keep an archive strategy where year-old emails are moved to an archive PST.
4. Archive PST files moved to NAS and DVD.
5. Using Outlook Rules, I am able to keep the current PST to less than 1GB.
6. I have two PST files, one for work and one for personal.
I am running the preview of Outlook RT and I think the huge pst issue is why there is an additional option on the setup screen for email accounts, where you can choose how long to keep offline messages(1-6 months). I think MS put that in there to overcome the space limitations of the Surface and working with psts, so it must automatically clean it out to keep it small.
I use the the Mail app and Outlook RT and I am normally an Outlook fanboy and couldn't wait to get it on my RT since that is all I use at work. However, once I got it set up, was not that crazy about it because it is not optimized for touch like the Mail app is, since it is still a desktop app. Don't get me wrong, you can pick and select via touch, but its a bit hard because some of the icons and such are small still.
I still find myself using the Mail app when I want a simple interface without all the clutter, which in my mind, is what the SurfaceRT is all about. But if I am doing a lot of work, I will use the Outlook RT client.