There is no difference in speed between PCIe 1.0 and 1.1. Why SuperMicro said it is PCIe 1.0 I don't know, but it doesn't matter.
Yes, the use of two lanes each for input and output add up to 5Gb/s, the same as the older single PCIe lane Marvell SATA chips, when used on a PCIe 2.0 board.
