I would say Harris is a lock,but if they can find someone that can return kickoffs better or just as good as he is, they will not need him for that Job, but what locks him in is punt returns, the only one that can return punts better is Dez, unless they have added someone that can beat him out. But I would say he is a lock due to his return skills.
Beasely on the other hand has shown he is a decent slot WR, the only problem with him is, if he cannot beat his man withint the 5 to 15 yards he is not that effective, but he has has a few passes 20yds or longer, but he was wide open and could be seen by Romo. Have you noticed that Romo cannot see Beasely when he is 15, 20 yards or more down the field especially if the defensive guy is running right behind hhim down the field.