No the +0.4% will always be reflected in the price of GLD, in other words if spot gold is going for $447 at the moment, then chances are the real time tick in GLD would be around $44.87 or $44.88.
I don't know the answers to the other questions, I do know that they sold 2.3 million shares in the initial IPO and will from time to time sell more. Their prospectus is rather lengthy and I've not read it, if your interested and have time on your hands, you can thumb through it, it's filed with the SEC at www.sec.gov ; Right now there's a big controversy of whether or not GLD actually has the amount of gold bullion in its' possession that it should or if it's just another paper derivative.
However, the people responsible for this claim that they will exchange actual bullion for your shares if you own over 100,000 I believe, it might be 10,000 though, I think I've seen both numbers posted...
One things for sure, this index does a good job at tracking the price of actual gold, and it has added more liquidity to the gold market (IMO), as well as interest.
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