2 Gigabit Ethernet combo Ports means RJ45 and SFP both. But if we use one SFP or Ethernet port from those variants, then their corresponding RJ45/SFP port will stop working. If we use both SFP ports, then their corresponding internet ports will stop ...

This concept is not clear yet. What the meaning of "2 Gigabit Ethernet combo"? Are those ports support RJ45 and SFP both? If answer is yes than how a RJ45 port support SFP?      

That means PL means = Partial POE+ and PP means = Partial POE. Am I right?