I do agree with you about him using him seeming to display some incompetence and lack of planning in some of his choices: the bite light, the cheap holster and wierd open carry, not being prepared to cover the nest cam with spray paint or having a screwdriver in his pocket to take the nest cam off, the bizarre glove situation where it didn't seem possible to be able to use the gun or anything else requiring some dexterity, the list goes on.
And, because of all of those things, I initially thought he was bumbling, seemingly incompetent amateur and thought something seemed off-kilter with him.
In the last few weeks, though, I started thinking that he had spent a great deal of time planning this crime. The video was released of him being at the house prior to the crime and seeming to test NG's security system with the nest cam to possibly see if the police would be called. Then, the time lag between when he was initially on the porch and when movement was detected at 2:13 am suggested that he may have planned to go up to the nest cam and then wait in the bushes or somewhere to see if the nest cam alerted the police or NG. His masking seemed to be multiple layers and, if so, he masked his facial features fairly well. I inially didn't think that he had paid attention to it being a full moon but after somebody commented on how he'd be so much better able to see the area where he dropped NG off, that made sense to me and I was impressed that he thought about the moon. He had something in his pocket that I thought might be a walkie talkie but it also could have been a Wifi spammer, police scanner or something else that he had thought would be useful. He clearly left his phone at home and didn't just turn it off. And the fact that he didn't appear to leave DNA in the house also made me think he had planned much more carefully than he initially appeared to have planned.
Anyhow, while I do agree with the things you mentioned that seemed to display his incompetence, I've started thinking about the above things I mentioned and that in order to get away with this crime thus far, he did a lot of careful planning.
JMO