Just thought I'd chime in on the transports thing.
Just prior to the standard deployment method it mentions that units may be deployed inside buildings, fortifications or transport vehicles within their deployment zones.
It's pretty tenuous logic, but we've generally played that as the vehicle is deployed first and then the squad is deployed into it. Obvious restriction is that dedicated transports can only have their respective troops deployed into them.
As you're deploying into the field, we treat this as having to declare which transport you're deploying into.
That said, I have played games with the hidden cargo dynamic, and it never changed much in the grand scheme of things.
It's hard to put any hard and fast rules to it, but like everybody has already mentioned, I'd ask permission to play like this rather than expect it. Could always be a laugh for both sides!