There seem to be few things that might require you to gain root to change with N900, but I haven't found discussion about if there's any considerations to do while considering is you're really going through this.

Personally I've been on-and-off user of linux with my laptops (mostly if I get bored and want to try something new) and I have Ubuntu server running in my study so I have some understanding about this topic, but I'm not even close to any expert.

So lets say I'm considering enabling the HID Bluetooth profile when I get my hands on my N900. Wiki has guide for it and part of it is gaining the root.

What implications there actually is once the root user is enabled in N900? Common sense tells me that I need a good password and also I shouldn't touch anything I don't know about.

But since we're now talking about a a device that has also a phone in it etc, I'm a bit more cautious and would like to know if there's anything else I should know.