I've seen an argument by a group of people once who claimed that Theodoric the Great was in fact an emperor and acknowledged as such by the Eastern Emperor,the group used the sending of Western Imperial Regalia to Theodoric as evidence to that.What's your take on that?
I think it's a bad interpretation of what was at stake. A Barbarian couldn't be considered as a Roman emperor, because it opposed two kind of political identity and citizenship.
Theodoric himself recieved a lot of roman titles (Consul, Patrician, Ausustus, Comes, Magister Militiae, etc.) that were (diversely) used by other Barbarian kings, such as Gundobad or Clovis, whom subservience to Constantinople was theoritical but more or less accepted*, but the imperial title was really out of question and it was never contested for centuries.
The misinterpretation over the return of regalia comes, IMO, to this essential part of Roman-Barbarian states relationship.
Now, what the sending of Roman regalia in 497 meant, because it certainly meant something, is a good question.
It's to be put in the context of why Odoacer was considered rebellious by Constantinople : having chased off emperors seen as usurpers by Constantinople, Odoacer generally recieved a similar treatment from the imperial court (Patricius and Rex) and concieved his mandate over Italy as similarily to how Theodoric did, the rightful maintain of the Roman state in Italy, under mroe or less technical suzerainty from Constantinople.
But, he eventually bet on the wrong horse supporting Leontius, Zeno's legitimacy being disputed, and the support of a still wealthy Italy against his rule (the accusation of mistreatment of Italo-Romans are essentially bogus) was not something the emperor was going to accept.
So, what was at core was the replacement of an independent subservient king in Italy, by another subservient and hopefully less meddling king in Italy. You'd note that between 493 and 497, Theodoric ruled over Italy without regalia of the western Roman state : the replacement of Odoacer by Theodoric didn't undermined the potential threat of a not-that-controlled Italy to ERE, and Theodoric supporting the pope against the emperor in the 490's, on the matter of the Henotikon, certainly didn't help.
Eventually, it was a complex three-sided exchange in the 490, with Gelasius, Theodoric and Anastasius being dependent on each other for what mattered their respective influence on Italy, and giving the regalia back in Italy in 497 was a way to satisfy everyone : Anastatius' overlordship was confirmed, Theodoric's legitimacy as well, and Gelasius found the pontifical power strengthened.
These regalia certainly didn't conferred an imperial title to Theodoric (it simply doesn't appear anywhere), but does highlight the "imperiality" of the Italian patricianship and kingship, both in suzerainty and structures (due to the Roman Senate, and being in the core of the former western Roman state), that wasn't as present elsewhere in western Romania (safe, maybe, in Africa, but that's another discussion). As such, it's rather a marker of the right of Ostrogoths to consider themselves rightful rulers of Italy under Constantinople : it's likely that Ostrogoths interpreted it as giving them the control of Illyricum (that was given to the eastern Roman state but occupied by minor Barbarian kingdoms at this point) and (maybe more rightfully, in a first time) a sign being
primus inter pares among the Barbarian kingdoms as well.
The acknowledgement of Clovis as Consul, Patricius and generally rightful ruler of Gaul by Constantinople is eventually one of the consequences of the fall-out between Ravenna and Constantinople, in a way to show to Theodoric that giving the regalia didn't meant that Ostrogoths could meddle in Illyricum as they pleased, and that Anastasus didn't considered Theodoric as his second in western Romania but in Italy proper (which while it didn't really prevented Theodoric to pull a de facto protectorate on the Gothic kingdom of Spain as well a tight relationship with Burgundians, possibly helped to force the decline of Ostrogoths).
Long story short : this conception is IMO, altough the transmission of regalia is not anedcotical, a misunderstanding on how Romano-Barbarian relations worked, on the nature of the imperial function, and a tendency to construct arguments from assumptions and pseudo self-evidents truths by ignoring litterary sources.
*Basically, they entierly accepted to be considered as lieutnants of the emperors on the West, as long the emperor didn't tried to make them effective subservients lieutnants.