No mention at all of Riflemen's flamethrowers? That's hardly a fragile platform, even if it's doctrinal, and it makes them a brutal unit in narrow maps and kinda kills the cover play in mid-late game.
Always use Attack instead of Attack Ground if possible. That is, if you target neutral structures, abandoned vehicles/team weapons which are in line of sight.
Attack ground is useful only when you can't actually click your target (when it's out of sight for some reason, or cloaked), if you want to target the most bunched-up part of an enemy squad instead of the auto-acquired entity, or if you need friendly fire.