DECA operates at lower frequencies, so a typical 1GHz splitter will work fine. Moca goes up to about 1.6GHz, so a 1GHz splitter could theoretically attenuate it too much. In my own home, I use old 1GHz splitters, and Moca still works fine. But I don't have any really long runs.

Amps need to be Moca compliant, unused ports should be terminated, and POE filters should be used at the POE and before any devices that are not Moca compliant, like tuning adapters and such. Mixing in OTA brings anther set of issues, but usually nothing that can't be fixed with POEs and diplexers.

In my very limited experience, Moca is very reliable.