I see the smartest way to work is to create a catalogue to import images into you want to work on, even if you only want to work on a few images at a time. The import process in C8 is very fast, so it's hardly any slower than loading a single file.
nope, the smartest /for "us"/ way is the way like ACR works - you do not bother with "creating a catalogue", you designated once what do you want about sidecars, etc and forget it.
Then you can return to them and re-work/export them whenever you like in the future.
somehow I can perfectly do this with ACR, with SilkyPix, with RPP, with Iridient, with whatever... and all that w/o "catalogs" or "sessions"... and no - I do not mind having "sidecar" files.
Using parametric editing like this is surely one of the great advances in digital photography workflow, rather than being stuck with having to work at individual images.
dear, every raw converter is parametric... every single one (even for example the old versions of ACR that were modifying some raw files /
the content, of DNG, like destroying the embedded thumbnail written by camera's firmware / w/o warning), you will be hard pressed to name one that is not /I dare you/