2. They have, new Apple laptops now use a USB-C charger that has a separate cable, rather than a fixed attachment point.
3. The 15" has increased by an hour.
4. USB-C is a standard, and is backwards compatible via cheap adapters/cables. USB-A ports are not forwards compatible, and cannot be used for charging, thunderbolt, display port, etc.
5. They have. Both 13" and 15" are smaller externally with the same screen size.
6. RAM, I agree with. My 2011 17" MBP has 16GB RAM so I don't know why they aren't up to 32GB yet, at least in the 15". I doubt 10TB is feasible as SSD in a portable device this size.