Damn... I was typing a huge reply here and accidentally closed Firefox when I was doing some more testing...

Well, this time I'll edit all in UltraEdit 1st!
1st, thanks Jeff but that won't be necessary: last night, after reading the other posters' answers in here, I went ahead and bought RightClick.
However, there are a few notes still worth mentioning...
Bugs: As for number 1 and 2, have not yet ran into them so far.
Bug #3 (tab key), I did not have it happen but somehow Firefox got closed when I started typing this answer (first letter of original post was a W); so I'll have to see if something weird like that happens again. A noteworthy point is that I have RightClick set to pop up on pressing Win key (just win key, not win+something).
"New" bugs (these all on the retail version 1.20 b739):
4) Level: moderate nuisance
Additional menu bar is displayed when RightClick is loaded manually.
I created a sub-menu bar where I replicated the existing items on the initial menu bar so that I could keep that main bar for my own programs. Whenever I open RightClick, for instance, after closing it to make sure it will keep my changes, that sub-menu is displayed immediately. It will only go away when I pop up the main menu and navigate to that sub-menu.
5) Level: moderate nuisance
Keyboard navigation does not work for items/folders that start in lower case letters.
I've replicated my existing menu structure in Righ-Click by using a few "Folder menu items" that link to my in-disk menu structure. Some of those are command-line utilities whose shortcuts I have all in lowercase. Apparently, I can't use the keyboard to navigate to those! This also happens when I browse Programs and try to access palmOne.
6) Level: minor nuisance
Opening the RightClick menu then pressing a key to navigate to 1st item of that letter then moving the mouse will permanently display the 1st item as selected.
E.g.: I have a sub-menu "N - Network" and pressing N will correctly navigate and select that sub-menu and open it; however, if I then move my mouse over other menus at the same level, even though the "N - Network" sub-menu closes, it stays displayed as if it was selected. This will cause 2 menus to be displayed as selected until I close the menu.
Also, a few suggestions for future versions:
1) Store menu configuration someplace else, preferably allowing the user to choose where, instead of doing as some programs and creating yet another "my whatever" under My documents. Ideally, I'd be able to select D:\MyDocs\Preferences\Stardock\RightClick as the location to save those settings. It helps a lot to make backups and get back on track after a re-format: all I have to do is point the program to that folder to read the existing configuration as I often don't format the other partitions.
2) Allow for a global custom-mouse-button to be selected and in other places, such as pressing the middle mouse button anywhere and not only on the desktop to open up the menu.
Note, aside from posting in this forum, I'll also be sending this text to the support e-mail.