In terms of the 'no code chip included' strips, unless the seller tells you what the code for the strips should be, there aren't many uses that I can think of. You can punch little holes into the strips and connect them with fishing wire, and create an expensive mobile. You can probably use them as toothpicks. Without the code chip (unless you have the same chip number from a previous batch that you've used, these are useless) with the Coaguchek XS.
In my personal case, my meter of choice is the Coag-Sense. It's a bit larger than the XS, isn't as well known, but in my experience is more accurate. Plus, one of the nice things about this meter is that a code is printed on the strip. When the strip is inserted into the meter, the meter reads the code on the strip, and is programmed to give an accurate result. This means that the code chip issue doesn't exist with the Coag-Sense.
I've been a bit lax on my personal view about testing weekly - but I'll make up for this next week when I have a minor sinus surgery and have to watch my INR daily.
Having some extra strips for bckup isn't a bad idea - but, with the XS, you have to deal with the Code Chip issue, especially if you're mixing your spares in with your newer supply so that you don't wind up holding spares that expire before you get to them.