Hmm... Your questions can be either answered, or deduced with a quick search for the Qi wireless standards and other info available about the charging system used.
So, my attempt:
1. Probably supports the Qi standard for low power charging, which would be a max of 5 watts.
2. Qi charging devices support low power (up to 5 watts, typical for mobile devices), medium power (up to 120 watts, for displays or laptops), or high power, supplying up to 1 kW, allowing the powering of kitchen utensils, for example.
3. I will again guess that the support for wireless charging systems can be modified by firmware updates. Notice that your question about point 2 being more than point 1 is a given, as the wireless standards provide for devices that can use a LOT more power than a smart phone
4. The wireless power consortium has a
presentation online showing that wireless charging can be just as efficient as wired charging. With that in mind - assuming that the wired and wireless options offer the same current, then you might expect that wired charging will be just as fast as wireless charging.