RSBM
I've been running through OP's 'final' version from the moment he woke until the moment he shot Reeva, but also seen from Reeva's point of view if she's following his script, trying to imagine why each part of the story exists or was added or changed. Of course, none of this is what actually happened IMO.
It starts with Reeva talking to him, establishing that she is in bed. Ok.
I can accept that Reeva got out of bed and went to the bathroom unseen and without saying anything whilst OP fetched the fans in, keeping his back at all times to the bed. Assuming she was sleeping on the right hand side (looking at the bed), she would have needed to get out at the bottom or on his side with all the clutter he has on that side of the bed, not forgetting his prostheses which aren't shown in the photos in situ. Let's also accept she took her phone with her for some reason (which we'll assume she picked up off the bedside table on the right).
I believe OP added the extra fan because moving one fan simply doesn't allow enough time for Reeva to get to the bathroom unnoticed if he isn't to go on to the balcony. I think he ditched going on to the balcony (he tells us this in two different ways in his bail affidavit so it was his story at the time) simply because he realised it would entail him opening the curtains, blinds and doors wider to get around the fan, filling the room with light, and turning to face the bed when he walked back in - why else would he have gone on to the balcony other than to get to the other side of the fan (perhaps the more logical side to carry it from)?
I think the fans are on in his version so that he doesn't hear Reeva get out of bed. Interestingly we never learn when the fans are plugged in or switched on. Of course, in reality they weren't on because they weren't found on but we see OP reinforcing the idea that they were on repeatedly in his story: he wakes and "noticed that the fans were still running" (why say that when they're supposed to be? He also notices the doors are still open - through the closed curtain, in the dark). He moves the fans and tells us again "the fans were still running, they were still running at the time". He needs them to be on.
Ignoring the balcony light that must have been partially illuminating the room at times during this process (he keeps telling us he closes the curtains) ...
He now has a problem. When Reeva opens the bathroom window he wouldn't hear this with the second larger fan blowing in his face. He can't have got back to bed or he'd have checked the bed and known she wasn't in it. So he pauses to put the jeans over the blue LED and at this stage hears the window sliding open and hitting the frame (more reinforcement). I think this is why the blue LED features. No other reason. Not because of the light disturbing him: it was probably in this state on many nights and something he would be familiar with. I included this in a previous post as part of him buying time, which was incorrect. It doesn't because she has to have cleared the bedroom passageway by the time he is facing the stereo (the passageway is now to his right). It's simply so that he can hear the window open. Why the jeans are on the floor is another story.
But why does Reeva open the bathroom window? If it's stuffy / humid and she's going to the toilet why not open the toilet window? We'll have to accept that she does open it and must also assume that she intends to close it after she's been to the toilet so as not to freak security conscious OP out.
Now I need to come up with an approximate elapsed time for him to fetch his gun, whisper, scream, shout etc. as he makes his way down the passageway to the bathroom and hears the toilet door shut. And then explain what Reeva is doing in this elapsed time and, if she flushes the toilet, why OP doesn't hear it. She knows there's no one in the passageway and bathroom because she's just walked through them. Assuming she's figured there's an intruder (when exactly does OP shout to get out of his house?), she must think he/they are downstairs or he's seen them from the balcony window ... so why doesn't she call the police when he shouts for her to? Why doesn't she talk to OP?
OP wants us to believe that she's scared (she has had a similar experience in the past), and she doesn't know where the intruder is, hence stays quiet.
It gets trickier so I'll work on this whilst taking on board any views.