Just as reference, and as a half-answer, following I'll summarize the options I've found. They came from two similar approaches, one from justinblanton.com and another from pugio.net.
Summing up, they both use FastScripts and this applescript:
tell front window of application "Safari" to set current tab to tab 1
tell front window of application "Safari" to set current tab to last tab
You'd have to save 9 files of this in
~/Library/Scripts/Applications/Safari, and give them all shortcuts in FastScript.
In my case, the 9th one in my case have just the "last tab" 1 line and no "try", and I got the SafariTabs.zip file from pugio and put it on root scripts, in
/Library/Scripts/Applications, rather than generating them and putting under Users.
To re-enforce: I don't like this answer because it uses third-party backgrounded application. I wish a way to tweak my system, could be using the same application, but not needing more stuff running on my machine in the background.