1 - If you use handsets which support video (SMT-i5343, Samsung Softphones, maybe WE-VoIP, or some 3rd party sip phones) you can establish a video call between handsets. If you use sip trunks and the sip provider supports video calls, and the other party does as well, you may be able to establish a video call external of the system to someone else who has a video phone.

2 - It has onboard basic VM, or you can purchase a VPU card which has all the functionality of the SVMI20i plus the CNF24 card.

3 - I've not seen anywhere the inbuilt ACD can do any of that.
You'll need a 3rd party Call Centre package. I don't even think the Samsung Contact Centre product can do those.