I wanted to send some comments about this process. I'll reply to your 5 tips.

Keep your Time Machine plugged in 100% of the time, so you always have your latest data

That is correct. You need to have Time Machine plugged in all the time. Otherwise, you are just throwing your data away.

Do not use an internal disk for a Time Machine. Convenient? Yes. Easily usable on an emergency computer? No.

I disagree here. It does depend on convenience but more importantly having two time machines is the best method here. Or like you, 3. I use an internal SATA drive in my Mac Pro as well as an external FW800 drive for time machine. One stays in my computer, the other goes off site. For the common consumer however you have to remember that the majority will own iMacs in which case, it's going to be an external drive anyhow. The problem is that most users will go buy some bulky drive that they will leave next to their computer, forever. I'm trying to discuss this flaw with a lot of people in the event that, as you mentioned, a fire burns your house down and you've just lost your Mac/Data as well as your Backup/Data. Hopefully people will at least consider firelites as a solution for once a week (or more) off site backup. Firelites are available here:

http://www.smartdisk.com/staticpages/PortableDrives.asp

Now, for the geeks at heart, or if you have a tower, etc with an internal drive, you can easily access the data on that drive from another computer with what I call the greatest USB device ever, the newer tech USB drive adapter! This thing is great, take any internal hard drive, SATA, IDE, etc and plug into it. Then connect the adapter to a USB port. Done. Available here:

http://eshop.macsales.com/item/Newer%20Technology/U2NV2SPATA/

Keep file sharing turned on just in case your computer’s video dies.

This is a good idea, however in the past (on older Macs) file sharing could sometimes eat up 10% of your cpu because of the constant broadcasting it would do over a network. I'm sure in todays quad core market this isn't an issue. Of course, the other option for those Leopard users out there is the VNC screen sharing. Just click the "Go" menu in the finder, select "Connect to Server" and type "vnc://IP Address.

If you have a home network like I do, I set everything with a static LAN IP address. Convenient to do? No maybe not. But then I create a text doc containing all my network settings, etc. This way, I never have to guess "Hey, who is 192.168.1.180?" I know that is my Tivo.... And in the same point, I can easily map stuff to various computers in my router and on top of all that, I know the IP of the machine I'd want to remotely VNC to and control it's screen. Great for headless servers and those mac book pros where the screen dies......

Spend the money and buy multiple drives for Time Machines.

At least two. Internal is great for 100% of the time if you have a tower. More than likely you'll have an external. Make sure to take it off site.

Be aware that if a computer repair replaces your motherboard, you likely won’t be able to use your old time machines for backing up. You can get the data off, but likely not put more data on, depending on the size of the drive.

Of course if you really need this level of help, call an expert. Mac consultants like myself are always available to help you. No, this is not a plug. Just a mere fact that you have help from professionals that care about your piece of mind. Don't call Geek Squad. At the very least, call Apple at 1-800-SOS-APPL and find out what your support options are with them. If they can't help you, call a Mac tech. We'll get you going.

Matt