1.In pitched battle or spearhead it is permissible to deploy veterans in a valkyrie and then make a scout move?

Regarding platoons-
2. In dawn of war does the entire platoon count as 1 troops for the purposes of deployment? or does one unit of the platoon count as 1 troops for the purposes of deployment?
3. can parts of the platoon be deployed and others held in reserve or does the whole platoon always come on the board simultaneously?

I have been trying to hammer these out for awhile and found a lot of differing answers, but things are still fuzzy for me. Thanks!