If I don't use the official branding, firefox will be called "Bon Echo",
You are correct, it will be named Bon Echo. It will still have the firefox name for the executable, but the familiar orange and blue "fox" icon will be no more.
We can however rebrand Firefox and make our own special version. We have the artists. We can make it very special. I think it would be nice to do so and have a custom default start page (stored locally) with links to everything a newbie would find important. Namely the VectorLinux documentation that is on the hard drive, the Vectorlinux homepage, and forums. And also have pre installed links to the same things if and when the user changes the start page to their own start page. Kinda like Konqueror does, putting useful information right up front when the user loads the browser.
Here's what the "Bon Echo" browser looks like.

Really nothing different other than the blue globe image. The start menu and taskbar icons would also be the blue globe. Which I might add are not trademarked and we would be free to modify. Honestly, our blue VL icon would slide right under the hood with no efforts. At compile time we could set what we would like our browser to be called. Instead of executing "Firefox" we could be executing "VL-Firefox" or whatever we would like.
It's a bummer, but I can understand why Mozilla is so picky about the logos. They don't want to be stuck with bug reports that aren't their fault. Distributors may redistribute unmodified firefox binaries freely (the precompiled ones from the Mozilla site). But if you compile a copy to distribute, or tweak settings of a precompiled version, they don't want to be associated with it. So therefore they want their trademarks removed to avoid confusion to the user. Debian debated with Mozilla for a very long time and finally dropped firefox and distributed their own re branded version... Ice weasel.
If the bigger distros can't get Mozilla's blessing, it's unlikely we will either. Mozilla does have a legal team and the finances to back them up. We on the other hand... well you know the deal.
easuter:Try skipping the "make install" part of the build. Instead launch this command from within the @topdir (mozilla).
make -C xpinstall/packager STRIP=/bin/true
When completed you will find a "firefox" folder within mozilla/dist. This will be a complete firefox installation. With only what is needed to run firefox. No includes, pkgconfig, nothing. Just like Mozilla's official builds. That's how to achive a 7 MB package. Well that and --enable-strip --enable-strip-libs --disable-tests --disable-debug --disable-installer added to your existing config. You will still need to create /usr/bin with a sym link to the firefox shell script in the lib folder. You will also find a firefox-2.0.0.6.en-US.linux-i686.tar.gz sitting right there containing all the same files that can be unpacked and run anywhere.