1) Wait for BTS-X wallet software to be released, and it will be able to import your AGS donation input addresses and PTS addresses from your existing wallets.
2) The wallet is not released yet. In the mean time you can check your BTS balance at http://www1.agsexplorer.com/
And its definitely not a PTS rebrand. Its got an entire trading interface allowing you to check the order book for each asset pair (eg BTS/BitUSD), buy, sell, short, cover etc.
3) No definite release date yet - I keep thinking "just a couple more months". They are going to make the shares liquid first then enable BitAsset trading afterwards. Someone please correct me if they know a more accurate answer.