Appreciate all the input. While I agree a nice AVR would be the way to go in the long run, it's not in my budget at this time. There's always next Christmas. You listening, Santa?
Given that and based on my (admittedly questionable) research, here's my current connection scheme:
Cable Coax --> TiVo Roamio Pro (via splitter)
Cable Coax --> LG TV (via splitter)
TiVo Roamio Pro --> LG TV via HDMI 1
LG SJ9 Soundbar --> LG TV via HDMI 2 (ARC)
Oppo UDP-203 --> LG TV via HDMI 3
Apple TV 4K --> Oppo UDP-203 HDMI In (passthru)
xBox One --> LG TV via HDMI 4
xBox 360 --> xBox One via HDMI passthru (or HDMI switch box)
+Wireless Internet throughout (I have pretty fast 180GBs down)
Perhaps not ideal but can you think of any reason this should not work?
I don't like using a splitter, even high quality, for TV/TiVo input but don't see any other choice.
Thanks!