I think that is a very methodical approach. Of course facts can be interpreted various ways, and various actions can account for the same result, so we must be careful. Fitting all the pieces together in the simplest way possible, though, is the most logical and straightforward way to begin.
And account for what evidence you know. For example, you mentioned the chair. But what about the mattress that they took? Unfortunately, the combination of the perps being there for 20 minutes or so before the 911 call, and the mattress being taken away lead my mind to thoughts that I sincerely hope aren't true... Hopefully, the 20 minutes are as has been suggested, the perps trying to get information and/or valuables.
What still seems odd to me is that first they violently forced their way, killing JC, and eventually DC, yet in the end took Jayme away with them. Those two facts just don't seem to fit together. Two different MOs in my mind. Which means taking Jayme may well have been an on-the-spot impulse move, for whatever reason.
Some unsolved cases just stick with me. Libby and Abby. Lizzie and Lyric. Michaela G. And others. This one hits just as hard, IMO. I keep checking news sources and here, hoping somehow that Jayme has been found safe and unharmed. Hoping. Hoping.