Beginner to Android customisation. Advice?

So I've had my Galaxy Nexus for a few months now and after flashing Google's yakju Jelly Bean image from yakjuwx I've kinda left it alone on the ROM/Root/Modding front. A post on this forum a couple of days ago with everyone's Android home screens has got me thinking that I really should be getting more into that side of Android. I have a few questions that I'm sure you lovely, clever people will be able to answer.

1. I have a hatred for anything that bloats up my phone or feels like it isn't integrated enough ie. Home replacement apps. I don't know what it is about it but to me it feels like this is the wrong way to go about it. Is this logical?

2. What is the best way to start getting into this stuff. Should I just root and start flashing random ROMs or what? I get the impression that AOKP is a good ROM to install custom themes etc. but are there really any ROMs that don't compromise on the stock Android experience that I love so much at the moment?

3. What is the best way to back stuff up if I am flashing etc. The main things I want to back up are:
i. Spotify Playlists (not sure if this is possible but to redownload them every time is a right pain)
ii. Apps (again, my WiFi isn't unlimited so I'd like to avoid redownloading all my massive apps (Hello Asphalt 7!)
every time I try something new)
iii. Text messages ( I imagine this is what many backup solutions have)

The feeling in one also extends to my view on everything. If stock Android is the only way to have an uncompromised experience then I don't really want to sacrifice it. I'm hoping that many people are on the same page as me. Basically if I'm changing something I want it to be at the lowest level possible.

Thanks in advance guys. And I hope all your marvellous replies help other visitors to the forums!