Did you know that the thriller genre has action while the suspense genre has danger but not necessarily action? I had not even considered the difference between the two genres, but of course it is true. I wish I had the kind of analytical mind that can cut through these things at a glance. On the other hand, I'm not so bad at symbolism.
The rhythm of a novel is the rate the reader reads, the speed at which the novel events occur and unfold. Dialogue can speed things up very nicely. Pacing is the length of time between moments of conflict. Though a protagonist may not know what his goal is on the first page, he jolly well ought to know by page thirty, and hopefully, earlier than that. Every step afterwards should be a step towards that goal. Interest is maintained and heightened if he encounters obstacles that must be overcome, and other characters will usually have a different set of goals that collide with his.
These things sound so simple when put on the page like this, but trying to "see" what is happening in the half-written novel is a different matter altogether. This is where the skill of the writer comes in, though I suspect some would say it is where a good editor tells you where change is required. I can't help the sneaking feeling that a) I would love to have a good editor and b) that a good writer should not need a good editor to point out where things could be improved. Call me conflicted!