Thinking of using this hotel, would appreciate any feedback on the security I would be likely to encounter (security guards by elevator, card access needed for elevator, etc.). Thank you.

When you enter the MO from valet you do not need a key to get to the lobby on the 23rd floor. The lobby and the bar are both great places to meet your date. You will then head to a different set of elevators to go down to the rooms. The elevators for the rooms require a key but do not have security guards.  
Hope this helps! Beautiful hotel

or the 3rd floor Mozen restaurant; then take the second set of elevators to your room. The 23rd floor is the main lobby with the Tea room and Mandarin bar. The bar is another nice place since there are usually a lot of beautiful women in the bar and very easy to blend in. Have fun.