The discussion in this thread reveals the reasons why we should ditch Thunderbird.
My initial reaction was "no, for gods sake - no you can't remove Thunderbird", but after a while I had to agree with the arguments there.
After several requests finally agreed to write a post about the Gentoo installation.
There is a nice, well written handbook that will take your hand and install gentoo for you, even if you don't have any experience or knowledge. So this post is bit redundant.
A weekly backup strategy is necessary step to avoid huge data loss in case of an issue.
There are many open source programs that will help you to do that, but why do you have to rely on a 3rd party program when you can create a small script and or program that will achieve the same result ?