There isn't much realistic about RDI when you stop and think about it.
The most surreal is an image of a person who lives in the same house scratching their head and then raising a finger and saying "Oh, I'll write a ransom note, and I'll make it 350 words, 1500 characters long"
I wouldn't do that, and I know you wouldn't do that either.
Things only get sensible when you can identify an actual motive. Even if you identify a motive for JR or PR killing or staging a killing, you still have to prove they did it. RDI doesn't even have a known motive, let alone proving PR or JR did it. Therefore, claims of RDI are no more sensible than claims any given neighbor did it. Remember that the R's house had doors and windows and everything, and that we know this crime happened at night when most people were sleeping.