Migrating from Ubuntu 14.04.1 LTS to 12.04.5 LTS

I decided to abandon Ubuntu Trusty Thar LST after about two weeks of usage. I was pretty upset about it. This is what I wrote when I made the decision:

I actually have to do paid work on my laptop, so it needs to be as reliable and as fast as possible.
Ubuntu Trusty with gnome session flashback was great. Really. The only little tiny problem was that it lasted only until I had to really depend on it because of my job. My job, that is 99% spreadsheet and internet browser work. Opening 10-20 chrome windows during a single search process takes all the memory, and freezes the system. Firefox is not really that better than chrome in memory usage. And Libreoffice... the spreadsheet I work with is like 2000 rows by 40 columns data and another 6 sheets of database queries made with functions. Libreoffice just could not handle this. It was terribly slow, lagging when scrolling, saving took up to a minute, and all 4.x versions crashed regularly.
No, this is not something anyone would recommend to do your job on. Not in 2015.

 I was planning to abandon Ubuntu at all, and choose a lightweight alternative, probably one that is based on Ubuntu. Then I realized Ubuntu Precise Pangolin is supported up to 2017, so I thought I'll give it a try before completely saying good-bye to Ubuntu.

I set up a similar environment as on Trusty. In Precise, it is gnome-session-fallback that gives back the Gnome2 environment. It can be downloaded from Synaptic Package Manager, which can be downloaded with the sudo apt-get install synaptic command in the Terminal, which can be opened with the Ctrl+Alt+T command.