Hey, the porch speakers would likely be powered by your # 6&7 Channel's- you designate your sbl and sbr channels as your zone 2 when you set up the new receiver( assuming it has the capability, most do)
Optical is digital.
Zone 2 feeds often don't have the ability to pass through digital signals (1712 doesn't ), so keep that in mind.
Sounbars are usually self powered so, connecting via digital shouldn't tax your 1712's amps at all.
I'm not a fan of outboard eq, the 1712 likely wouldn't have the capability anyway to run one. Ck with denon online- the specs are all there.
As long as you can connect an Ethernet cable, your good to go- if not, use an Apple TV or airport express to stream your later model iPod .
All hdmi devices will connect to your receiver and a single cable will go to the TV .
Get a harmony remote or similar to coordinate all of this electronic wizardry.
Cheers, Mac