I generally dislike how time travel is dealt with in TV and film, I wish (in general) that they would steer clear. But I also understand that people are a little more happy to suspend disbelief for the sake of entertainment than I am too. Looper was about the most perfect representation of time travel on screen, I think.
Saying all that though, it was a better representation of time than most manage (including the already mentioned Legends of Tomorrow) so I'm going to let it slide. As a metaphor for how the show is going, I dig it, Barry trying to fight his demons, then trying to accept them, finally realising that he needs to let his demons go.
I haven't seen Arrow yet but what I think I'd like is the following...
All the "Arrowverse" shows jump forward in time.... say 5 years. Ollie has the opportunity to have matured into his role as dual Mayor and Green Arrow, chilling out a bit more, having drawn a line over his time as a castaway and the 5 year evolution to a new mature self in Star City. And then, Barry is back, a changed person (depends how much you know about the comics to know how this will be approached), less the "Everything is doomed" and more the very guy we saw when he chose to confront Savitar and offer to try to help him rather than destroy him.
I don't know how well the writers would operate without the emo-drama crutch, but I'd like to see them try at least.