ornamentis: ablative of separation.

To sum up, Cicero's whole argument hinges on the jury's acceptance of his version of Caelius' relationship with Clodia, since the relationship gives Clodia a motive for lying without adducing external political considerations. At the same time, the relationship reduces the scathing attack on Caelius' character to an attack on his one relatively defensible episode. But Cicero must depict this relationship without making any quotable admissions of Caelius' misbehaviour. The dilemma is the ideal vehicle for Cicero's argument since it (1) allows him to posit the affair without admitting it, (2) gives the illusion of exhaustive, invincible argument, and (3) contributes a unique persuasive resonance; the repetition of the dilemma form, like the incantatory repetition of a phase, endows with a specious validity the ideas it evokes. Thus, dilemma allows Cicero to keep his version of the relationship always before the jury, to conjure with it, and to do so without ever admitting in any quotable form that Caelius was actually involved in an unsavoury situation. The fact that dilemma occurs with such extraordinary frequency in the Caeliana is thus essential to the success of the persuasive strategy, and to the remarkable power of the speech.
("Reason, Resonance and Dilemma in Cicero's Speech for Caelius", Rhetorica 7(1989).328)

Quintilian was the first teacher of rhetoric to insist on the importance of moral excellence in an orator .... Cicero, a more practical orator living in a more competitive age, advocated in his rhetorical writings not so much the abstract qualities of honesty and uprightness, as those which may ingratiate the orator to his audience: culture, knowledge of the law and of history, memory, wit and humour.
("Occultatio in Cicero's Speeches", American Journal of Philosophy 86(1965).175)

Usher then examines one particular stratagem, occultatio ("covering up"), which is used to introduce weak arguments or false evidence. The preceding lines (52.28 - 54.16), culminating as they do in breuitatis causa relinquo omnia, are a classic example of occultatio.

Usher concludes:

Occultatio is but one of many figures of thought that Cicero uses with consummate mastery; but it differs from most of the others in that it seeks to beguile the intellect rather than the emotions. It endeavours to create the impression of an overwhelming amount of argument or evidence available to the speaker, which must on purely logical grounds incline the jury in his favour. (192)

All the subjunctives in these lines are subjunctives of unreal condition, the pluperfects referring to past time, the imperfects to present.

domi suae: locative.

haec x 3: epanaphora.

The adjectives in line 19 virtually balance one by one those in line 21. If, as is often claimed, use of adjectives is one criterion for judging a writer's merit, Cicero ranks high.

Cicero voices his distress at the sudden, violent, unavenged death of Quintus Metellus Celer at the peak of his career. In his last moments Metellus grieved over the disasters awaiting Cicero and the Roman state. Had he survived, he would have resisted the machinations of Clodius even to the point of killing him.