I'll echo what randy says -- I wouldn't chance using "screen cleaner" solution with your ZT. I generally wipe smudges away from my VT with a dry microfiber cloth (or add a tiny bit of water for stubborn smudges). You never know how those cleaning solutions will interact with the coating on your screen. I've used them on my glossy LCD and they've caused lots of horrible streaking.
RE: your receiver and a new 3D blu-ray player, the TX-NR609 is not that ancient, it's from 2011....it will support 3D video pass-through with no loss of quality, audio or video. There's no need to connect HDMI direct to the display and run an optical cable back to the AVR; in fact, doing that will actually cause a loss of quality over just using HDMI since optical does not have the bandwidth to support lossless audio tracks like DTS HD-MA or Dolby TrueHD. The only weak point on the NR609 is that it only uses Audyssey 2EQ calibration...if you're interested in a size-able uptick in sound quality, I'd look into a new AVR with MultEQ XT or XT32, like the Denon X4000.
if you're really interested in direct-connecting the blu-ray player to your ZT60, then you can get a blu-ray player with dual HDMI: The Oppo BDP-103, Panasonic DMP-BDT500 (recently discontinued and available for very attractive pricing), Sony BDP-S790, and the Samsung BD-F7500 all have a dedicated HDMI out for video and separate for lossless audio. There is really zero benefit to doing this if your AVR passes through 3D, but it's an option.
ht Panasonic 60" ZT60, Monitor Audio: Silver RX6, RX Centre, Radius 90HD; Martinlogan Dynamo 700, Marantz SR5006, PS3, Oppo BDP-103D
2ch Sony KDL-32W650A, Sony BDP-S1000ES, Marantz PM8004, JVC T-X3 tuner, Monitor Audio Silver RX1, REL T3, Apple TV, Peachtree Audio DAC•iT, Sennheiser HD598
lr Panasonic 50" ST60, Sony BDP-S5100, Apple TV
pc Energy CB-5, Audioengine D1, FiiO A1