I think there were wasted opportunities in other series as well, so it is not charactheristics for Voyager only. I guess I personally pay more attention to Voyager's lost opportunities, because I care about the series the most.
About developing their own cultural identity and its consequences when they were back in the AQ - this is something I recently thought about myself. Janeway wanted to remain "as Starfleet as possible", but it is true that their circumstances were unique and their crew was unique. So it would have been inevitable for them to have the cultural identity of their own, which would have been "un-Starfleet" in a way. However, Janeway was such a Starfleet's golden girl, who expected a lot from herself and then some. So her feelings to Chakotay, her XO, would have really made her to struggle with her own convictions more. It would have been brilliant dimension to her character.
About developing their own cultural identity and its consequences when they were back in the AQ - this is something I recently thought about myself. Janeway wanted to remain "as Starfleet as possible", but it is true that their circumstances were unique and their crew was unique. So it would have been inevitable for them to have the cultural identity of their own, which would have been "un-Starfleet" in a way. However, Janeway was such a Starfleet's golden girl, who expected a lot from herself and then some. So her feelings to Chakotay, her XO, would have really made her to struggle with her own convictions more. It would have been brilliant dimension to her character.