I’d disagree with the statement that Boheme suffers from a bad libretto. It sounds to me like you suffered from bad direction and/or bad acting. The clues to Rodolfos jealousy and temper are, in fact, in the text, even as early as act one *with Mimi. A good director should bring these out.
I didn't dislike the acting at all, or especially the direction. The Zeffirelli production, though, is excessive and campy. It distracts from the libretto—though setting the second act amid such hubbub makes the jealousy and temper hard to discern.
The crux of the problem is the subtitles. They cut eighty or ninety percent of the libretto, including the comments to which you refer, and the more they translate the faster it flashes on the screen. I imagine Rodolfo's comment "Sei mia!" at the end of the act might have been elided, the only suggestion of jealousy that I see there. Certainly telling someone you've known a half hour that they are yours is possessive—though the case for jealousy and temper is not obvious to me in the first act—only in the second, and only now that I actually read the libretto. Please cite the lines in Act 1 that I may be missing; I just read the first act, but nothing really stuck out. Are you thinking of this passage from che gelida where in reference to his poetry, dreams, and fantasies he comments?
Talor dal mio forziere
ruban tutti i gioelli
due ladri, gli occhi belli.
(I do not speak Italian, but it is variously translated "But sometimes my strong-box / is robbed of all its jewels / by two thieves: a pair of pretty eyes," and "Yet sometimes from my safe, / all my gems are stolen / by two thieves, a pair of lovely eyes!" — feel free to offer your own translation if these are inadequate.)
The second act is where I think you can really make a case for this. At first, kind of being a dick:
Mimì
(ammirando la bacheca di una bottega)
Bel vezzo di corallo!
Rodolfo
Ho uno zio milionario.
Se fa senno il buon Dio,
voglio comprarti
un vezzo assai più bel!
(Rodolfo e Mimì, in dolce colloquio,
si perdono nella folla)
Translated:
Mimì (Admiring the showcase in a shop) This is a beautiful coral necklace!
Rodolfo I have a millionaire uncle. / If the good Lord wills it, / I will buy you a necklace / that is twice as beautiful!
(Rodolfo and Mimì, deep in sweet conversation, get lost in the crowd)
The next time we see him comes the most obvious invocation of jealousy, and I underline the relevant text because it's so difficult to translate.
Rodolfo
(con dolce rimprovero, a Mimì)
*Chi guardi?
Mimì --
(a Rodolfo)
Sei geloso?
Rodolfo
All'uom felice sta il
sospetto accanto.
Mimì --
(a Rodolfo)
Sei felice?
Rodolfo --
(appassionato a Mimì)
Ah, sì, tanto!
E tu?
Mimì
Sì, tanto!
Rodolfo: Who are you looking at?
Mimi: Are you jealous?
Then comes the difficult part. One translator renders it: "Suspicion lurks not far away, waiting to pounce on a happy man." Another: "The man who's happy must be suspicious too." A third: "The man in love is always jealous, darling!" I'm of course indebted to any native Italians who might offer their own rendering for the general edification.
Update: my godmother who studies Italian Renaissance art tells me she likes he second one, but would soften it to: "The man who's happy is suspicious too"
Mimi: Are you happy?
Rodolfo: Yes, very! And you?"
Mimi: "Yes, very!"
The jealousy is most clearly stated when Rodolfo remarks, seeing Musetta's shenanigans:
Rodolfo --
(a Mimì)
Sappi per tuo governo
che non darei perdono
in sempiterno.
Rodolfo --
(to Mimì)
Know this now, for your future
knowledge that I would never find
it in me to forgive constantly.
Mimì --
(a Rodolfo)
Io t'amo tanto,
e son tutta tua!...
Ché mi parli di perdono?
Mimì --
(to Rodolfo)
Ah! but I love you very much
and will be yours forever!
Why do you speak to me about forgiveness?
The dynamic recalls the third act of Otello, which had premiered some nine years before Boheme in 1887, and which Puccini would have been intimately familiar with—it was the highlight of Verdi's career, and probably remains the highlight of all Italian opera, with the possible exception of Poppea. The remarks add up to someone with the potential for suffocating jealousy. Yet even here I think I stand by my central critique of Boheme, that Rodolfo's temper and jealousy—and more to the point, their relationship
as such—is only gestured at speculatively and retrospectively, and not definitively illustrated in some hypothetical missing act between acts 2 and 3. The night in Paris is, after all,
literally their first date. What the phuck? Is that all we get to see of them pre-break up?
That said, the production's 2nd act privileged the spectacle and glamor of Paris above all—the jealous comments were stifled by the gaiety surrounding them, by the cross-talk of the other characters, and by the subtitles not drawing the audience's attention to
the most important thing happening dramatically: the flaws in Rodolfo's character.