I think that it was easier for Cinderella and Thomas because Regina is not actively going after them. The curse created a situation where they were not together, but that is it. With Snow and Charming, Regina is actively doing everything she can, everything, to make sure they don’t end up together.
I think that the Queen was going after everyone, but only because they supported Snow. Like Snow said Regina isn’t a queen anymore and it seems like the people have decided to support Snow and Charming in the fight against Regina. Though i do think that really Regina is hurting everyone else just to hurt Snow because like Phee said Snow is Regina’s main concern.
If we rewatch the pilot, when she announces the curse. It is directed at Snow and Charming first, then everyone else present at the wedding. So both are correct everyone is collateral damage and yet they are all directly effected too because everyone in connected in someway or had helped them (Snow and Charming). They are directly effected because of guilt by association to the happy couple. Their guilt by association makes them collateral damage.
It is like the what came first, the chicken or the egg argument. Nobody is going to be right at this point until we hear Regina actually says, “Hey Cinderella I did not mean for my curse to hurt you, but since you are friends with Snow and so won’t get a happy ended…you won’t too.”