I don't really want to turn this thread into a lengthy debate about terrain rules in 7th. This is exactly why I advise a pre-game discussion about the terrain. In an attempt to clarify my position, however, I'll propose a couple of common examples: The rules for ruins on page 108 of the BRB do not include much detail. What do you do with multi-storied ruins that don't have a base? Is the bottom level considered "difficult terrain"? Prior editions of the game had rules for this, but this edition doesn't. Additionally, although you correctly point out that there are terrain datasheets, they are limited in number, are very specific, and are limited to Games Workshop produced terrain. If you are playing with a scratch-built terrain piece, or a forest that is just a cluster of trees (whether or not they are on a base matters here, too) and is not a "Twisted Copse" or a "Battlescape," the only terrain dataslates that depict trees at this point, there are no rules for forests. These are the kinds of things that a pre-game conversation can resolve without turning it into an argument in the game.
As I said, I don't really want to turn this thread into a debate about terrain. If there is interest in such a debate, however, I would be happy to start another thread in the tactics section to expand on this topic.
Thank you all again for your comments! Does anyone have any more tactical suggestions/insights to add to the OP? Thanks again.