I'm planning to buy a netbook, and I am considering to install Ubuntu on it. It would mainly be used by my wife at home for web browsing and email at home (lightweight is important, hence a netbook!), and we'd occasionally bring it along on travels (mostly as digital photo dropzone).

I want to use Ubuntu instead of Windows because I'm sick of all the Windows hassle and updates. I'm not concerned about Windows applications; I'd switch to native alternatives as far as possible because really only Firefox and something like Picasa are needed.

I'm considering an ASUS Eee PC 1001P or an MSI Wind U100 or an Point of View Mobii II (click the links for specs; nevermind that the rest is German). I'm not in the USA.
Whatever I buy will most likely have Windows 7 on it but no optical drive. I would also buy a large-ish USB stick but not an external optical drive.

1. Should I (and can I) install Ubuntu alongside Windows 7, or remove Windows?
2. If I remove Windows first, how would I be able to reinstall it if I change my mind? Can I make a backup? Is a recovery CD usually provided?
3. Should I choose the regular Ubuntu, or the Ubuntu Netbook Remix (UNR)? Does UNR allow me to install additional applications just as easily?

Note: I'm asking about Ubuntu vs. Windows; let's skip the hardware discussion for now.

Edit: I'm assuming that Windows is already installed; if it isn't then I would only install Ubuntu and this question is irrelevant.