Thank you for joining the Graphics Community. I can sure help with you.
Before clarifying your questions I would like to like to know the full model of your Office Computer including the processor model, this will help us to answer your questions accurately.
Processor: Intel Core i5-4570 CPU @ 3.20GHz
System Type: 64-bit
Windows 7 Enterprise, SP 1
Does that help?
Thank you for the information.
Regarding your first question you need to double check with Dell support it this model comes with two Display Port 1.2 and Multi Stream Transport support, according to the specs it does but double check with them first. For your second question, remember that Intel® HD Graphics 4600 included in this processor support a maximum of 3 displays, that would be max you can achieve with the Hub too.