I'm putting together my new home theater (shipped boxes landing for the next week). I've opted to run my components through a combination of an Oppo HM-31 switch and HT-CT100 sound bar so I can get basic Linear PCM decoding while I pause to evaluate beefier sound solutions.

One effect is that all my components end up being switched, and all end up in the same TV input. Unfortunately, that means I'll have two game consoles sharing settings with two video players. I'm pretty sure I'll want different video settings for those two very different uses, particularly since the TV I bought is infamous for gaming lag in non-Game mode, and inflexible picture settings in Game mode.

I could go HDMI from all components to TV, optical to the sound bar, but I believe the TV's optical only puts out 2-channel for connected components, which doesn't really cut it for me. I'd also like to have a setup where I can just drop in a good AVR in the future when I have more room for speakers.

One thought that came to mind was buying an inexpensive 1x2 splitter (was thinking the Monoprice HDP-102) and simply splitting the output of the HT-CT100 to two different inputs on the TV. That way each input can hold appropriate settings for movies/TV and games, respectively.

Anyone know of any major pitfalls there, or have a better suggestion?

No major pitfalls, but HDMI can have problems with splitters. Otherwise your idea should work. If not, you can return the splitter.