Jormones,
To answer your questions.
1) The iDrac7 Express doesn't support using the dedicated iDrac port, you would need to install Enterprise with the license.
2) If there is anything in the network chain that is 10/100 it will drop the speed to that. Verify that the switch and network are both running at 1000 itself.
3) Boot to the Lifecycle Controller and then select iDrac Settings, then click on Network. From there you can select the Nic.
Let me know how it goes.