Yeah I suppose, but then if you can't google "install openoffice on " then you probably shouldn't be installing stuff anyway
As far as possibilities you are hindered by processing power vs regular pc but you gain smaller size, more easily powered and a price so low you could consider the device disposable (eg, send it up on a weather balloon). I'm considering a project with a robot arm which isn't practical with a pc. Conversely I can't use an rpi for playing games or connecting up loaRAB of sata drives.
Well I want mine primarily because I'm attempting to learn Python and it would be handy to have a device I can muck around on. But yes I can see your point.
Probably not that simple with the RasberryPi (unless it's already been compiled for it). You have to remeraber that the RP runs on the ARM architecture which is very different to your home pc that will be an x86. So you can't just download any linux software from the internet and expect it to work (as it will most likely be compiled for the x86 arch).
Until someone who knows what they are doing gets hold of the source code and specifically compiles it for the ARM architecture and makes it available to the masses.