FWIW (and that's from a UK perspective so not sure whether/to what extent it applies to Australia/NZ), I've found agents at STA and (even more so) Trailfinders to be up to speed and understand complex requests much better than the "customer service" staff at Expedia/Opodo, or the high street "holiday shops" (still known as travel agents although they aren't that anymore).

Budget or not, some of the tickets they sell are quite complicated (e.g. RTWs in conjunction with intracontinental passes), so they tend to have an idea about things like booking classes and fare rules, which are concepts alien to many other "travel agents", in the UK at least.

As for working in the travel industry...I'd probably enjoy some part-time work at an agency or a proper corporate position with an airline, but anything in between doesn't sound too attractive to me.