Okay, so I solved part of the sudoers list / root password problem. Turns out 
that I had not downloaded quite all the sudo packages, particularly some of 
the tde-trinity packages, or kde-trinity transition packages, or something in 
that lot. 

Now my password and permissions behave as usual, so my life can continue. 
Still, just to get up to speed with the rest of the smart folks, I would like 
to figure out why I have problems with that. It makes no difference for me 
now, in my day-to-day life. I try to stay offline when I don't need 
something, and use my machine for other things. However ... it might be good 
to know, as well as more secure, and it might be that I ought to learn this. 
I tried to follow what the Linux Bible says, but (just like with the other 
Bible), it seems to be full of contradictory advice, and I end up being told 
that I don't have permission, when I know that in fact I do have it, that 
this is my machine. 

As for the firewall, I got gufw up and running, once I solve that sudo 
problem, by downloading the trinity sudo packages. Now I just need to figure 
out how to find where Firestarter keeps its iptables files. I have my rules, 
of course, which I have kept meticulously collected and curated now for 15 
years, but ufw or gufw doesn't seem to recognize these, and I don't see how 
they relate to iptables, even though I have read that firestarter uses 
iptables. If I can get ufw/gufw to use my firestarter rules, then life would 
become tolerable again. 

I wonder if developers can be persuaded to create firestarter-trinity 
packages, updated to handle ipv6? Gufw does have some nice features, but it 
is good to be able to see my connections, in real time -- especially when it 
seems that it was being hijacked, or derailed, by a tor exit node. It seems a 
pity that such a great package should be deemed obsolete, and not worth 
adapting or upgrading, but there may be technical reasons that make it 
unavoidable. 

Bill