1) Is drop pod a dedicated transport? YES
2) Units embarked on it is counted as one unit? YES
3) Can it choose not to deep strike? NO
4) Must it always come in as reserve? YES
5) Can it ignore the reserve rule? Please explain if the answer is no. YES
But bear in mind, if you don't have any model on table at the and of any player turn. You auto lose. So make sure to deploy at least one model and survive the 1st player turn (if you go 2nd) to avoid this.