Hi, this is my first post, though I've been reading this forum for years, whenever a case interests me.
In regard to JW, I don't find the Lowe's trip odd at all. From an article I read it sounds like JW asked SS for a job and so SS created this position as a way to help the kid out, rather than SS having a burning need for a driver/personal assistant. (And I seriously doubt SS fired an existing driver to give JW a job.) So it seems likely to me that JW's job was to drive SS around, and run errands as needed, but that there was probably a fair amount of down time, waiting around and being on call for when he needed to ferry SS somewhere.
I'm going to assume, for the sake of argument, that JW is a complete innocent. SS instructs him to drop the money off in the garage. JW says, hey, should I wait around and drive you into work? Obviously SS can't have that, he needs to get rid of him, so he says something like: no, I'm going to drive myself, I need to do a few things, but I'll be over at the dojo this afternoon, so just go hang out over there until I need you.
I forget the exact address of the dojo, but I google-mapped it before, and my memory is that basically across the street from the Metrotech & Sully shopping plazas where Lowe's is. Granted it is across a "big" street - Lee Jackson Hwy/Route 50 - but in that plaza JW could be back at the dojo within 5 minutes if SS needed him. Sure, SS may have given JW a specific errand to run at Lowe's, but it seems just as likely to me that JW was killing time (basically his lunch hour) while staying close enough to the dojo to be at SS's beck and call. I spent a few years in Chantilly - moved away 3 years ago - and I went to those shopping plazas a lot. If the dojo is where I think it is, that's where I'd go to hang out and kill time. (And as a woman, I was under the impression that Lowe's and Home Depot are where men go when they have time to waste...)