Thanks guys, that helped to clarify the situation for me.
On the subject of LXDE, it seems PCManFM is now able to use a Trash folder now instead of deleting files entirely...that's a good sign for me. I looked into it once before LXDE ever took hold as a full-fledged desktop environment, and that was one of my sticking points. I know that might sound trivial, and I'll admit I've dismissed LXDE very quickly without giving it a fair shot, but I've mostly avoided it because its design goals appear to conflict with my preferences:
I ultimately prioritize a desktop environment's simplicity of use over the simplicity of the underlying software: Whereas KDE is too "busy" for me, LXDE places such a strong emphasis on performance and memory consumption that it may be dropping features I actually enjoy to achieve it. Since I'm more on the mobile workstation side of things than the netbook side, minimizing system requirements isn't as much of a priority. Gnome 2 was bloated under the hood (and Nautilus has always been wayyyyyy too slow), but the interface at least struck a balance I was comfortable with. It didn't distract me with hundreds of options for tweaking, but it included enough graphical configuration front-ends ("Control Panel" kind of stuff) and panel applets (e.g. weather, investment) that I had everything I needed close at hand and rarely felt restricted.
I tried XFCE a couple times, and it always seemed lacking on this front. I felt it was missing some of the "Control Panel"-esque functionality I was looking for, and there were little things that bothered me: For instance, I never got the hang of editing the right-click menu to let me use the desktop like any other folder, and Orage was a lot less flexible about the kind of information it could display than I would like (I like seeing the day of the week, date, and time at a glance). Thunar is much faster than Nautilus, but the last time I tried it I was treated to a choice between obnoxiously huge navigational icons in the toolbar, or none at all. These are nitpicky issues, but it just didn't feel like home to me. (In comparison, Gnome 3 and Unity are total nightmares: I'm task/data-oriented rather than application-oriented, and I rely on the desktop as a "messy working area" before moving files to the well-organized parts of my filesystem. That's aside from routinely using multiple instances of the same application...)
LXDE appears to be similar to XFCE in this manner, and it has an even stronger emphasis on a small footprint, which might not be the best for me: My sweet spot for applications is more in the gedit ballpark than the Leafpad ballpark, so to speak. I could replace a bunch of basic applications with Gnome/Mate equivalents, but loading the resulting heavy-weight Gnome/Mate libraries into memory would defeat the purpose of having a lightweight desktop altogether. I'd also have a bunch of programs with duplicate functionality that didn't fit with the desktop, and I imagine the "Control Panel" would still be light on tools.
TL;DR and conclusion:
All that said, I'm going to have to compromise somewhere, and I'd rather not resign myself just yet to waiting months and months for software updates. I think I might take your advice to heart and give LXDE a shot anyway, dibl. Maybe it will surprise me! Even if it doesn't, I could try installing Mate alongside it and hope for the best. If Mate breaks on update, maybe I'll get lucky and be able to boot into LXDE instead of a recovery shell.
