I think the theory you have come up with is very possible, bvstrish. It fits well with what I have been mulling over. I'll also add that MS may not have known about whatever CWW was doing and may not be the one who told CWW that TS had downloaded the evidence to her home computer. Someone else in the office who was involved may have told CWW, or it may be that he could tell remotely that it had been done.
JMO
BBM
I'll give your question a try, Bobby. You may be right that CWW did know that TS would be coming home (because he could access the schedule or MS innocently mentioned it), but was hoping to get in and out of the house before she arrived. It may have taken longer than expected to destroy or erase the evidence on her computer. She arrived and it got ugly.
OR, CWW could not access the information on her computer and erase it, needed to wait to have her do it, and then killed her to prevent her from telling what she knew.
OR he knew from the beginning that he not only needed to erase the information, but kill her because of what she knew, which would have led to a first degree murder charge, I expect. So I'm not sure he originally planned to kill her, based on the second degree murder charge. The charge can change, I suppose.
JR being along indicates to me that CWW knew it could get ugly and wanted JR to be the one to do the dirty work.
I think that regardless of whether MS knew or did not know what was going on, CWW had to be at the funeral to avoid suspicion. Jodi Arias attended a memorial for Travis Alexander and acted like she belonged there. What a shock that was to his friends, who suspected her from the moment his body was found! Evil indeed.
JMO