Hi BruceBanner
I think you have captured a pretty good understanding of the tradeoffs. Some folks just keep an sRGB workflow.
So here are my thoughts in separating out the choices.
1) 8 bit vs 16bit (or whatever your camera supports i.e typically 12 or 14 bits)
Doing at least you initial editing in 16 bit has real advantages to pull out details from shadows or highlights. You can actually keep it in 16 bit up until you do the final exporting.
2) sRGB vs wider gamut color spaces. You might be just fine with what you said about yours and your client's needs. So it may be just a matter when you convert to raw. LR does not change the color space until you export so you would want to turn on soft proofing with it set to sRGB to be able to edit and see the end result. If jumping to PS, you could also turn on soft proofing and edit there. This gives you slightly more control over the look of the image rather than converting earlier.
3) If you stay in higher gamut color spaces with sRGB proofing turned on, you can always save a version with the wider gamut and a separate version when exporting.
4) Note that JPEG only comes in to play when you want to export and not before. It only supports 8 bit yet it does support all color gamuts. Not that other options can include PNG or TIFF yet due to the reduction in storage space with the lossy compression of JPEG, that is the most common. Given that the lossy compression introduces artifacts, I suggest this is not the version you use as your long term archive. I would size the image for what is needed for viewing/printing and at the highest quality compression for image quality that does not cause problems for web viewing etc. As you have seen from my chart and what you have stated, exported in sRGB with the profile embedded is about the best you can do given the uncontrolled environment of your customers.
5) There are some trade-offs yet you could convert to sRGB (you can still stay in 16 bit) earlier and then you would not have to mess with soft proofing. This is an approach that can be considered for your workflow. It gives you less control with subjects that might have high saturation such as flowers in brighter sunlight yet may not be a problem for the majority of images.
So I don't thing there is a right or wrong or best and worst, just some tradeoffs to consider and take the one that best works for your needs. Wouldn't it be nice if there was one "best" answer and not even have to make the decision. Life is rarely that easy 
Hope this helps and best wishes on whatever path you choose.
John Wheeler
