Magno ea fletu et mox precationibus faustis audita. ac si modum orationi posuisset, misericordia sui gloriaque animos audientium impleverat; ad vana et totiens inrisa revolutus, de reddenda re publica utque consules seu quis alius regimen susciperent, vero quoque et honesto fidem dempsit. Memoriae Drusi eadem quae in Germanicum decernuntur, plerisque additis, ut ferme amat posterior adulatio. funus imaginum pompa maxime inlustre fuit, cum origo Iuliae gentis Aeneas omnesque Albanorum reges et conditor urbis Romulus, post Sabina nobilitas, Attus Clausus ceteraeque Claudiorum effigies longo ordine spectarentur.
impleverat – ordinarily, this verb would be in the subjunctive mood (being part of the apodosis of an unfulfilled condition). The indicative mood helps to make the failed outcome seem more vivid.
gloria – “pride,” at their appointment as foster parents to the young princes.
de reddenda re publica – it is worth noting that Augustus talked about restoring the Republic on several occasions. When he assumed power, Tiberius also said that he would not be emperor forever. His motives here could even be seen as laudable, but Tacitus denigrates them with the description vana et inrisa.
in Germanicum – an abbreviated form of in memoriam Germanici, itself a good example of variatio following memoriae Drusi.
decerentur – fragments of this decree are recorded (see picture) by the 19th century epigraphist Wilhelm Henzen. The phrase culpeus argentarius (“silver shield,” line 10) might be evidence of the plerisque additis, and consequently posterior adulatio.
ferme amat – “usually is accustomed,” where amat = solet.
pompa – a causal ablative, “due to the procession… .”
Albanorum reges – the first king of Alba Longa was Aeneas’ son Ascanius. Later, Rome and Alba Longa would clash, with the Romans destroying the Alban city and absorbing its population to double their own. Many famous Roman families originated from this wave of immigration, including the Julii.
Sabina nobilitas – according to some traditions, the Claudii family had Sabine origins, through Attus Clausus. The Sabines were a mountain tribe who inhabited an area north east of Rome in its early history.
These words were heard with much weeping, and soon with auspicious prayers. And if he had put an end to his speech, he would have filled the hearts of his audience with pity for him and glory; but falling back to pointless and so often laughable topics, about the need to restore the Republic and that the consuls or someone else should take over governance, he took away belief from the genuine and honest bits as well. For the memory of Drusus the same things were decreed as for Germanicus, with many things added, as later flattery is usually accustomed to do. His funeral was especially remarkable due to its procession of statues, since Aeneas, founder of the Julian dynasty, and all the kings of the Albans, and Romulus the founder of the city, the Sabine nobility behind, Attus Clausus and images of all the other Claudii were observed in a long line.
Magno ea fletu et mox precationibus faustis audita. ac si modum orationi posuisset, misericordia sui gloriaque animos audientium impleverat; ad vana et totiens inrisa revolutus, de reddenda re publica utque consules seu quis alius regimen susciperent, vero quoque et honesto fidem dempsit.
Marks are awarded for the quality of written communication in your answer. 
nullo metu – shows that Tiberius is in denial about Drusus’ ill health, or that he is purposely rising above suspicion of murder.
firmitudinem animi ostentaret – he could well be making a show of fortitude in the face of adversity.
etiam defuncto necdum sepulto – but this is extreme behaviour (emphasised by etiam).
consules…admonuit – he refuses to accept insincere tokens of condolence.
victo gemitu – he shows great emotional self-restraint, in contrast to the senate (effusum in lacrimas).
senatum…erexit – he motivates the senate by his words (oratione continua) as well as his actions.
non quidem sibi ignarum – he shows an awareness of how he is perceived by others, and why his behaviour might be deemed peculiar (recenti…senatus).
neque illos imbecillitatis damnandos – he claims to empathise with the behaviour of others.
fortiora solacia e complexu rei publicae – he is dedicated to his role of princeps.
vergentem aetatem suam – he is entering his twilight years.
unica praesentium malorum levamenta – his affection for Germanicus’ children is moving, and he makes a warm gesture (quibus adprensis).
precatusque sum…foveret – he resettled them out of his concern for them, Drusus (sibique) and the state (posteris).
disque et patria coram obtestor – religious/patriotic.
clarissimis maioribus genitos – respects tradition/heritage.
suscipite, regite…explete – he can be firm and authoritative.
ad rem publicam pertineant – more concern for the state.
Magno…fletu…precationibus faustis – his speech rouses a powerful response from the senate.
si modum orationi posuisset – but he does not know when to stop.
ad vana et totiens inrisa revolutus – he ruins everything with habitual, tiresome utterances.
quoque et honesto fidem dempsit – he undoes the support he won with the first part of his speech, in effect undermining any positive impression which had been created.