I shall try to answer.

1. Stem cells are totipotent in that they can be made to be any cell in the organism. Totipotent cells have not been differentiated to a specific lineage. Progenitor cells are a step towards being differentitated in that they are called pluripotent and can make any cell of that lineage (muscle cell lineage, blood cell lineage, neuron cell lineage, etc.).
2. Progenitor cells are found all over the embryo. In fact, Stem Cells are only found in niches of the embryo. The 4 cell stage of many zygotes are totipotent. In that, you can separate the 4 cells and they will form 4 perfect organisms. After the 4 cell stage, differentiation of the cell has begun and the cells when pulled apart will follow only a lineage (a mass of mesencymal tissue, or endodermal tissue, or ectodermal tissue).
3. All I know about that is that Obama has allowed tax dollars to be available to researchers to use stem cells. There is strict guidelines as to how they acquire the embryos for the stem cell culture/lines to be made. What these are, I do not know. Something about being the discards from a fertilization clinic (either very old embryos, or genetically not viable for birth).
4. Using the right biochemicals (from growth factors, to hormones, to environmental media), the stem cells can be differentiated into the cell of choice. This cell of choice will be made without defects and implanted into the organism, with the possibility of providing the good cells for the bad cells, or the cells that even have all died out.
5. Progenitor cells are cells that usually replicate themselves asymmetrically to be another progenitor cell and a cell towards whatever lineage they are to be (the muscle cell, neuron, blood, etc.).
6. Progenitor cells can also replilcate symmetrically, by providing two progenitor cells (still only pluripotent and not totipotent) and no cell lineage cells at that time/location. They can proceed to become asymmetrical in their replication when they encounter a signaling factor that is secreted from the environment (say another cell that is not nearby, but is available after the cells divide and push there way towards the far away cell) and they proceed to differentiate into the cell lineage.
7. Same as 6.
8. Yes. Look at 6.

Thanks kolean, I learned something today… 🙂

-Dory