I can buy the idea of an accidental collision by a US sub that was there to take a look at the excercise but to take out a Russian sub in order to test a super weapon? Nope.

The Russian military has been underfunded since the fall of the Soviet Union. The bulk of the Russian Navy stays in port with a handful of units putting to sea for short cruises. A lack of proper training on how to handle torpedoes is a more likely cause of the Kursk sinking.

If the Varyag is brought into service, it will probably serve more like a training ship and an experience gatherer before the Chinese put their own carrier into service.

But sometimes you have to wonder why they just didn’t do this with the Minsk and the Kiev earlier. What is it with the Varyag that makes it much more preferable? Size?

The Kiev and Minsk were not designed to operate CTOL aircraft. They were really heavliy armed helicopter carriers. The Yak-36/38 wasn’t a completely successful VSTOL design. China apparently wants a CTOL carrier so Varyag is it.