Just wondering if the second computer (offline) is really needed if you only plan on doing a few transaction per year.
I was thinking just copying/backup/print the 12 word seed and whenever I need to spend the money, just load up a Live CD, install Electrum, restore from seed, and sign the transaction that will be later on broadcasted online with my other computer.
Are there any issues with this method?
It sounds very much like you are already using another computer offline. You are running it in a RAM OS with a Live disk and signing your transaction to be broadcast with your other machine. Nothing wrong with that approach depending upon where you are getting the Electrum software you install once a year or so. Just as food for thought here; if you spend any time online with that machine while you gather what is needed to "sign" those transactions you are sacrificing what makes a completely offline computer with Electrum so special. On the other hand you can gather the needed software using your other machine and verify file integrity, etc.... and THEN use that software from a disk to run everything on your signing computer without ever taking it online. Just my suggestion, others may differ.