Haha, yeah I had that issue for a while when I first got it.

It was "wait if I rely on the N900 to make/receive a phone call I can't install completly random devel software since if it screws the tablet up when I'm out and about I'm screwed!"

But then a few days later I forgot about it and installed some random devel software. Though I am more careful about what I install, which makes it harder to test apps, since sometimes it's the ones that make your device unstable that need the most testing.