It would be nice for us to have the ability to select what technicians get what notifications. 

"Alert Technician by e-mail when a request is assigned" - This would be nice to control which technician wants to get these notifications. Not everyone wants to be spammed with emails, yet some people would like to have these.

Same goes with "Alert(or Notify) technician by e-mail when there is a new reply from the requester" - This would also be nice to control per technician.

Basically most of the Notification rules for technicians would be great to control per user (similar to how it is done for Alert group members by e-mail when a new request is added to the group, through the Support Group settings and adding individual users).

Can there be Notification Rules per site as well install of globally?

The second request is for closing rules. Why can't we change these per site or support group? There is another branch of our company that uses SDP with us and they don't follow the same work flow as us, so it is a pain for them to follow the closing rules that we have.