Overall, the rules are very well-written and seem to cover most situations, but I had a few things I wasn't sure about when it comes to terrain:
1) If a model is on Elevated terrain, it ignores other units and terrain when measuring line of sight. Does this mean that other units ignore units and terrain when targeting it as well, or is it one-way only?
2) For Deadly and Taxing terrain, do units suffer any ill effects for remaining in contact with it (or even occupying it) in subsequent turns, or is it only on the initial collision?
3) When Exposed terrain becomes occupied, does it stop being Exposed, since the unit is considered to basically take up the whole thing? Or does the unit "sink in" and no longer block line of sight?