I know this question has been asked so many times, but I don't know what should I do in my case with those tutorials available everywhere. This is how my current situation looks like:

Right now I'm using Linux Mint 13 Xfce installed with:

1. 500MB of /boot
2. 2GB of swap
3. 15GB of /
4. The rest of my space is /home with no space left in my hard drive

And I just got a Ubuntu 12.10 live CD from my friend, and I intended to install it alongside my Linux Mint. And I want to select something else in the installation process. The question is:

1. I want to use the same /home partition for Ubuntu and Linux Mint with same user but different directory because I don't want my configuration files conflict with each other. For example my username is Budiman and I want a directory named /home/budiman-Ubuntu for Ubuntu and /home/budiman-LinuxMint for Linux Mint. How can I do that?
2. I read it somewhere said that I can share /boot and swap with multiple Distro, is it true?
3. How can I make another /root directory for Ubuntu since I don't have any space left in my hard drive? Can I resize the /home partition without losing my data? How can I do that if it's possible? Now I've used 10-20% of my /home partition.

I really hope somebody can help me with my question, if possible with a full tutorial starting from install with something else step until completion of the process. Thanks before :)