Thank you both for your quick response. Apologies for the confusion.
As an active internet businessman and computer engineer, I am online 20+ hours per day. As such, I often have two, sometimes three, browsers open simultaneously, each serving its own set of functions. I have finally gotten to the point of turning gray from Firefox’s memory bloat, so I once again have picked up CB in its place, remembering its lightweight, efficient footprint. (I also run Chrome, Chromium, Safari, etc. as my projects dictate).
Within CB, yes, I do employ tab browsing and have gotten it to where I am quite happy with that setup. When I am running CB, I have both windows and tabs engaged, with each set of tabs facilitating a specific project. I open a new window (and associated tabs) for a new project.
Here, then, is the specifics of my previous question. Yes, I can click File> Open New Window to launch a new window for CB, and this works just fine… opening without the sidebar, as desired. However, I prefer to make use of my (Quick Launch) icons and nearby navigational toolbars.. quicker, I guess. When I click on the CB icon in my Quick Launch toolbar, Cometbird opens with the sidebar, which I have to then close.
As kluelos stated in the reply, if it is true that I can have either bookmarks or sidebars, but not both.. that is fine, because I never use sidebars and would prefer to never see them.
Not a big deal, but since there seems to be an about:config option to tweak the other settings within CB to fit it a bit better to my needs, I thought I would at least ask, simply to save the few clicks necessary to close the sidebar when clicking CB from my quicklaunch.
Many thanks again – much appreciated – keep up the good work 
Eriq