Can I issue commands to my entire team instead by per squad basis?

In most matches, I have found that the objective location changes quickly. This can take some time and become rather mind numbing if there are 10+ squads in a match!

Is there an easier way to give orders to my entire team, rather than by each squad? If so, how?

Unfortunately no. It seems that they added Commander Mode in BF4 to appease the fans of the older Battlefield games that have been clamoring for Commander Mode to return for years.

This time around, though, squad leaders and commanders don't really have that tight-nit relationship they had in previous Battlefield games and the commander is only able to talk to the entire team or everyone in the game, rather than individual squad leaders or all squad leaders at once.

The best suggestion I have is give as many orders as you can to individual squads (change them as you see the squad moving, not really based on what objectives need to be taken - since you do still get points for defending objectives) and just use Team chat to command the squad leaders.