The biggest problem with TFA...

It's the first chapter of a trilogy.
Yes, I know A New Hope is as well, but it wasn't truly designed to be. Lucas and Alan Ladd, Jr. had no idea if Star Wars was going to be a hit or a bomb. They were personally convinced it would be a success, but there was no guarantee. For all intents and purposes the original film is a stand-alone experience. There are no drawn out plot threads or character arcs. It's totally self-contained. Personally I think this leads to the biggest problems with the sequels, that there's absolutely no hint of what's to come. No Vader is Luke's father, no Leia is his sister, none of the retrospectively tacked on, make it up as we go along stuff that sort of bugs me. Those big reveals were never even questions or hinted at the ANH. "From a certain point of view," of course.
This film is not just setting up the next two films but everything that will be the new Star Wars that we will probably be living with for decades. If a lot of the plot feels familiar it's because it has to try remixing what's come before, including the PT, in a way that can provide a solid foundation. Cashing in on some nostalgia and familiarity is absolutely part of the formula, for better or worse.
And I also think that some of the issues we have, the unanswered questions or plot holes, will probably be resolved in VIII and IX. Why did R2 wake up? What's Snoke's agenda? Is the New Republic actually fragmented by the destruction of the capital? What did Han's death truly mean for our characters? What's Luke been doing and why did he run when he was most needed?
The questions in the original Star Wars were more like, "What's the Clone Wars? Sounds cool!" or "What's a Jabba the Hutt? Sounds cool!" They weren't necessarily anything the films had to answer. The big questions in TFA are far meatier and more integral to the story as a whole. So relax. Give it time. You'll get the answers. Until then, speculate away!