Ell' ne leur fait jamais la vie (see above)
Ne leur fait jamais de tartine
"tartine" is a slice of bread with anything spread on it but also a screed, a tirade or a slap -usually on the face. So you can understand "she never makes them a "tartine" either way.
Ils mangent quand ils ont envie
They eat when they feel like to
Et quand ça a dîné ça r'dîne
And when they had dinner, they have dinner again. The play on words is between "ça r'dîne" and "sardine" that sound alike.

S'ils veulent être maquereaux (see above)
C'est pas elle qui les empêche
De s'faire des raies bleues sur le dos
can be understood literally as "to have blue stripes done on their backs but "se faire" is also slang for "to lay/to do somebody", "raie" is also slang for female genitals. "raie" also means "ray/skate", then "their backs" can be theirs or the skates' and you can understand the whole thing as you like!
Dans un banc à peinture fraîche "banc" is a bench but also a school of fish.

J'en connais un qui s'est marié
À une grande raie publique
"une grande raie publique" sounds like "une grande république" (a grand/great republic) but "raie" (see above) + publique refers to "fille publique" = prostitute.
Il dit quand elle lui fait la nique
"Faire la nique" means "to cock a snook at someone" but the verb "niquer" = to fuck, so what is she really doing to him... that is the question.
"Ah! qu'est-ce que tu me fais, ma raie!" can be understood as "Ah! what are you doing to me, my ray!" but also "Ah, qu'est-ce que tu me fais marrer" = "Ah, how much you make me laugh / how funny you are!" knowing that "marée" (the tide) sounds also alike.

I hope I've covered it all.