Workflow, gimme some opinions

I shoot mostly jpegs because I like the file size, the ease in downloading, and I can make all the adjustments I need easliy. Shooting in RAW doesn't buy me that much more. It's just a personal preference. Here's my question.
I shoot the original in jpeg. Make adjustments and save. Then I save this 'completed' file to tiff. Is there any need or benefit to doing this? I usually don't come back and make any more adjustments to the file, but do open and close the file many times. I only do this for the real keepers, but I am wondering if there is really any need to do this. I don't think there is any difference printing from a jpeg or a tiff, no +/- in qulality either way.
I haven't done this, but what if I converted all my keeper shots to tiff right off the bat then made all my adjsutments to the tiff file. Does this give you the flexibility and file quality of RAW more or less?
Thanks for the comments and opinions.

Open the jpg. Save as a tiff or psd (whatever you prefer). Convert to 16 bpc. Edit. It does not give you the initial benefit of 12 bpc that raw offers, but you'll gain smooth edits by switching to 16 bpc. When you are ready to output to jpg for the web, you can convert to 8 bpc and save as a jpg with minimal compression (quality - 12) with minimal loss in quality.