I'd advise looking at talk.origins for these. The "Index to creationist claims" should have many of them, usually with useful links.
TO go over the points.
1) Meaningless wihtout the actual figures - which he doesn't give.
2) The expansion of the Sahara is not solely due to the coriolis effect (human activity was a big factor). I'm pretty sure that the Sahara is not the oldest desert either. Finally it is fallacious to argue that the age of the oldest currently existing desert sets a maximum age of the Earth.
3) The population argument is complete rubbish. A series of technological developments (such as agriculture) have improved our ability to produce food and to exploit the earth. Since our population is dependant on our technology more than time any argument that population provides a time limit is nonsense.
4) This is false.
5) I'm pretty sure that this is also false - but if it were not it would only mean that the earth was without the moon up to that point in time.
So 2,3 and 5 are all fallacious - the arguments don't provide a real maximum age for the Earth. 4 is outright false. And 1 simply lacks the numbers needed to support it.