Question 1 & 2: Yes, as TECHIE007 already said. You can store items on a PCIe drive and it will appear as a drive under My Computer.
Usually the reason for going to PCIe instead of a SATA SSD is due to bandwidth restrictions provided by the connector, as there are SSDs which can use up the available bandwidth. However, if crazy performance isn't your main need for going this route, just choose whatever is cheapest and easiest for you to work with.