The Force Awakens breaks almost all of those basic rules of MacGuffining.
Clarity. What exactly is the MacGuffin? Is it the map, BB-8, or Luke Skywalker? Not much time is spent on any of these items in the film despite them being central to the film. For example, Luke is important because he's a jedi. Once he rejoins the Republic, or the Resistance, something very vague will happens, so vague that nobody knows what it is, not even his enemies. Likewise, there's a map to Luke, but the map never matters until the end of the film. The gaining of the MacGuffin is supposed to feel like a big moment in the film, but in this one, which moment is it, and more importantly, why don't most of them feel like big moments?
Conflict. The MacGuffin drives the final conflict. In Episode IV, there's the plans to the Death Star, which leads to a showdown with the Death Star. The MacGuffin is directly tied to the finale, the final 15 minutes of the film. In Episode VII, BB8 and the map leads to a battle against Starkiller Base, which has nothing to do with either the map or Luke Skywalker. Essentially, Starkiller Base walks in from offscreen. That's the point where resolving the MacGuffin should reside and dealing with the implications of that resolution.
So the First Order is trying to get the map as well. Cool. That's conflict. What exactly are their PLANS once they gain the map to Luke Skywalker? We don't know. Will they blow his planet up? We don't know. Will they attempt to sway him? We don't know. What did Rylo Ken hope to get out of this? The audience needs to know what failure will cause, but in this film, we don't know any of the implications of failure.
Likewise, we needed to know what what failure to find Luke meant to the resistance. What exactly would he turn around if he were present? We really don't understand what good Luke would accomplish. I find it amazing that we don't know what success means for the Resistance who began the search for Luke.
Obviousness. Although a MacGuffin is obvious from the outside, for the most part, a MacGuffin should fit into the film as if it belongs there. That wasn't the case in Episode VII, where the MacGuffin of the map said, "I'm the MacGuffin." Its use felt too obvious, and its obviousness was amplified by the trope's poor use.
Maybe I misremember. Maybe there lines which explained what the First Order's practical intentions were towards Luke Skywalker. If so, please enlighten me.
The thing is, none of those things above matter, because the real story is Rey's internal journey, which I found rather muddled. With the introduction of Luke's light saber, we had a MacGuffin appear that seemed to replace the map. The light saber's introduction and vision provided an implicit promise that it could lead Rey to Luke.
I suppose that we could use a series of MacGuffins, all to push Rey towards Luke, but that sort of film would be structured differently from Episode VII's structure.