Unfortunately, it's still not available right now. As soon as our distributor has more information regarding a delivery date, we will update our website.

This is possible thanks to Ubiquiti's patented Power Multiplier® software. Often copied, never equalled. Seriously: the manufacturer's technical data states "60W (Excluding PoE output)".

If it's a 19" rack, yes.

Is mentioned in the technical data sheet under Downloads.

Unfortunately, I cannot report from my own experience (upgrade is only planned). I would take a look at this module: MikroTik S+RJ10 (Transceiver Module) According to specs it supports 2.5/5GBit. In general, Mikrotik makes good networking hardware. Whether this is compatible with Ubiquiti I don't know, but I would assume so...

This is even listed in the Early Access Store at Ubiquiti itself, where it sells out almost immediately if there are more units. Note that the Early Access Store only ships to the USA.

The Pro can be supplied with redundant power using an external power supply unit. The additional power supply unit is also in 19" format and supplies up to 4 units with power redundancy.