I've been in organizations that try many of these ideas, and typically they all fail.
Two sided printing - great until you realize something has to be printed one-sided, but you forgot the printer defaulted to two-sided and you have to reprint.
Restricting access - great, until someone needs that print for a customer meeting and has to spend 15 minutes tracking down someone with the authority to print it. Not only a waste of time, makes your customer question your capabilities.
I do recommend looking at your processes to eliminate waste paper (and time), but telling someone they can't print an e-mail to take to a meeting to jot notes on is self defeating. The 750 pieces of paper wasted a day costs what - $5 maybe? I have been eliminating paper in my office, more for the efficiency. I had people giving me a piece of paper saying exactly what they had just e-mailed to me, and entered into a database. I told them to stop the e-mail and paper, and just tell me it was in the computer - all I need. It was more for the efficiency and lack of clutter issue though.
I've also found I proof read best on paper. Have tried doing it on the computer, but I'm more efficient with a red pen and paper. Telling me I can't do that will just kill my efficiency.
As for the green aspect, trees for paper are farmed just like corn, soybeans and other crops. It is not like they are cutting down 200 year old giant redwoods to make printer paper. Printer paper is also highly recyclable, and contains recycled paper. Going crazy trying to save 750 sheets of paper a day is going to have zero effect on the environment, but possibly a noticeable effect on your business. Eliminate the obvious waste processes, put in a recycling bin if you don't already have it, and move on to bigger things, IMO.