Burden of Ages is a poor fit for a race that commonly spends its youth as special forces and party girls. I think it works well in a species feat if you want to represent the matrons and matriarchs but not so much for the poledancing asari.
If you read the Codex, you'll note that it points out that Asari are poorly suited to the stand-and-fight tactics of most other races, prefering hit-and-fade techniques. The fact that it requires longer/more game mechanical effort to regen vitality fits that particularly well. Also, BoA specifically refers to effects
, it doesn't affect standard vitality recovery rates as far as I can see. Even if it does, there's nothing about that which particularly impacts partying and pole dancing, which IS affected by their Resolve cap increase (an increase that also plays to my Resolve=biotics use skill mechanic).
Vorcha, Volus, Elcor and Hannar probably belong in an optional species category. I am of two minds concerning the Elcor's type. Beast fits what we see in game, but they are supposed to have reached space before the asari contacted them. Looking at the models though they seem to have hands that would be usable when they sit down. There may not be enough of a payoff to worry about it though.
There are a lot of conception problems with the elcor as a non-uplifted species, but that aside, I don't see the elcor making non-downtime tool using checks, which strikes me as a reasonable invocation of the beast quality. And yes, they're definitely the least viable PC races in terms of general utility, just remember that there's at least one hanar merc out there that almost managed to take down Zaaed (hence why it has abuilt in garrotte)