The magazine disconnect connect safety is nothing like on a Browning Hi-Power (absolutely nothing is! ) but yes, it can be removed.

The LCI is situated right along the left side of the receiver and can also be removed, which leaves a gaping hole. I believe that some aftermarket company sells a "filler."

Excellent point by Wee Hooker about the much easier ability to add optics as a genuine upgrade to the Mark III series over the Mk II. I constantly forget about this because I am particularly averse to optics on handguns. Just my personal preference and as I get older and my eyesight erodes, I will resist as well as I can!