Learn English – What does the phrase “Words to live by” means

I don't think the Seinfeld definition really amounts to any more than an opportunity for 'larky' humour.

In common understanding, a delicate genius would be much the same thing as a volatile or unpredictable genius. True genius is obviously quite rare, and most of us don't really understand it.

But it is common knowledge that genius/very high intelligence has a tendency to correlate with mental instability (e.g. van Gogh), and poor social skills (e.g. Newton)

In general I'd call someone a delicate genius if I wanted to highlight the idea of he/her needing to be handled carefully in order to get the best out of their special abilities. I'd call them an unpredictable genius if I wanted to indicate that even with careful handling you still might not get the result you want.

In either case, OP could consider it a (slightly back-handed) compliment. The implication is that OP is normally expected to do exceptionally well, and any lapse from that high standard must be down to the nature of genius, not his stupidity. But in context, it was probably a bit tichy (tongue-in-cheek).

What to do when you live in a shoe isn't really a "popular saying" across the world at large. Google finds only 31 instances of this quotated text on the whole of the Internet, at least half of which are simply duplicated references to the same original instances.

A related but far more common expression is living in a shoebox, meaning "in a small appartment". This probably owes much to the nursery rhyme There was an Old Woman Who Lived in a Shoe who had so many children, she didn't know what to do.

OP's (possibly quite localised) idiomatic usage seems to convey a sense of making the best of limited resources. I'm assuming when he gives this reply to someone asking why he doesn't have fast broadband, it's because he lives in a rural location where fast connections are unobtainable or prohibitively expensive.

My own guess is that OP's meaning has arisen circuitously from the original nursery rhyme context. Apart from lacking access to modern contraceptives, the old woman was probably poor, since people living in rural locations are on average poorer than those in the city.

When it comes to broadband, the economics become even more relevant. Even if you live in a tiny apartment in a city, you can probably get cheap broadband because the cost of wiring up the whole building become insignificant when shared between all the people living there. When you live in a farmhouse miles from anywhere, the cost of getting connected by cable can be astronomical.