from what I can tell:
2: PTS / AGS - I'm lost. Is PTS finished soon? AGS only gained by donations? Is it worth doing this (PTS donation).
You get shares of bitshares and future dacs from owning either PTS or AGS, they co-exist. PTS is not finished soon, they still get you future shares. AGS are only gained by donations. You can see if it is worth doing this by checking out one of the explorers (e.g., http://www1.agsexplorer.com/
). You get > 1 AGS/PTS, which is good, and there are fewer (at the moment) AGS than PTS, so you get even more bang for your buck.
3: Will PTS still be mined or BTS?
PTS are mined, BTS are not mined and are given to AGS and PTS holders at genesis block.
4: When is BTS released?
Snapshot of the PTS blockchain and AGS donations will be taken on February 28th, and BTS XT will be released shortly after. It is essentially a release candidate that will become the official BTS release if it is stable. Trades on BTS XT can therefore be real trades, so treat them like real trades (not testnet).
5: My plan was to invest into more mining hardware (CPU). Shall I?
hard to answer, this is based on speculation. Do you think PTS will retain value/appreciate? There are GPU miners now too that may be more efficient as well. It's really hard to say what will happen to PTS after 2/28.