The Flash Season 4: 7 Problems It Needs To Fix
6. Reduce The Couple Drama
This is a lesson that Arrow already has had to learn, so now it's Flash's turn. Romance in these shows certainly have their place, but if you have an excess amount of it, it will detract from the action/comic book focus. The third season of Flash suffered quite a bit from a consistent flow of scenes involving both old couple and new struggling with their own specific issues that really bogged down the flow of many episodes.
Although these moments do allow for certain characters to grow and progress in their own way, they often detract from the main focus of the plot. Each scene by no means has to cover completely essential, but having these 'couple scenes' receive more screentime than primary villains and side characters will lead to unevenness across the board.
Barry and Iris will/should always have a presence in the show, as it's an essential part of his duality of being Barry and being the Flash, but there's no need to overload the show with more romance with every other pair of characters. There's a place for love and couple-building, but no need to overload it.