D-Day and other questions

[MechaMaestro]

I've recently purchased Normandy '44 and am hoping people have more experience with the mechanics of the game to help me understand how to do better in invading Normandy, and many of the other games in the series.

Firstly, what's the real strategy with paratroops? When they first drop they seem effectively useless, and the following turn they seem to be unable to do anything useful on their own. I have Market - Garden '44 and they're usually capable of doing things and heading towards objectives by the following turn. Should I prioritize getting them assembled into their parent battalions or is there a way to use them effectively at company strength?

Secondly, is it better to have my units at the battalion level or company level? Is there any advantage to breaking them down or should I always keep them in a battalion?

Thirdly, does anyone have any tips for breaking the bunkers and pillboxes on the beaches? I feel like even Utah is a difficult beast to get out of and I have little hope for moving on to Omaha. All my naval assets seem to be completely useless as well.

Thanks to anyone who can shine some light on this!