Here is pic of a young lad's tank taken in Dunedin 2003 at the tank parade. I can't remember his first name but his surname was Payne (trying to give credit where credit is due)
a) no
b) cut back how much you feed rather than stop
c) get back into regular maintenance
d) no need, but why not? You can always do with more fish
e) you could if you want. Once you stop negleting the tank the worms will disappear
I have seen a number of tanks in old TVs and they look good. Just make sure it is well braced. A glazier will make whatever sized tank you need to fit the space. Don't forget you have to be able to access the tank.
They will also lose colour against light substrates or backgrounds as they try to blend in with their surroundings. That is why I rcommend dark gravel as the fish are more colourful.
No idea if it was finrot or not from the pics. Fin rot usually looks like the ends of the fins are going see through and raggedy then blood streaks form down the rays.
Might as well do another water change, it won't hurt.