A lot of historical media throws around the idea that ancient Roman patrician men came under censure for excessive interest in their own wives.
Dan Carlin's Hardcore History series mentions that Marcus Licinius Crassus was criticized by his political opponents for "loving his wife too much." (I've looked and I've been unable to find out who Crassus's wife was, yet alone how their relationship was) The documentary "Carthage: A Roman Holocaust" suggests that one of the senators who opposed the third Punic war was temporarily suspended from the senate for kissing his wife in public. Similarly, a great deal of media (Hardcore History, Wikipedia, some textbooks, etc) describe Pompey Magnus as "besotted" by Julia Ceasaris, and attribute more or less all of his political behaviour during that marriage to his affection for Julia, and suggest that this obvious devotion to his wife contributed to his waning political popularity during that period.
My questions are: Is there any evidence for all this? If so, how did the ancient Romans distinguish between appropriate husbandly behaviour and "too much" love? How seriously would this accusation impact a patrician's reputation, and therefore his political/military prospects?
Sort of. It is more a general concern that domestic pleasures were interfering with public obligations. Being overly affectionate with your wife would be no different than, say, loving to lounge in your garden too much, or the infamous love Hortensius had for his pet fish. All of these interfered with the ability of a senator to embody the ideal of the severe Roman task master.
It is worth noting that glimpses we get from outside the elite, such as funerary art, epigraphy and some literary works like Petronius show affectionate marriages.