Thanks to both of you for the thoughts! Based on your suggestions, I will probably upgrade the hotel in Cusco (JW Marriott) and look into nicer hotels in Lima. Seems like a 5 star experience is more reasonable than what I am used to expecting (but I wouldn't know very well

). The Belmond looks amazing and is on the coast, which seems great.
Miraflores is nice, but if you have seen Santa Monica there is no need to go there. Instead, I suggest staying right in old town on Saturday in one of the classy 5* hotels and explore the center on Sunday.
Sounds like a great idea! I wasn't able to find any nice hotels near the historic centre though, save for the Sheraton. Seems like most are in Miraflores or San Isidro. Checked using google, tripadvisor hotel map, etc. It must be my lack of familiarity with the city though- any suggestions?
I would suggest returning CUS-LIM on Thursday night to have an entire day in LIM. Personally, I would avoid airport in the morning and airport at night as driving out of LIM and into the city, and getting back in for your international dep. can be very time consuming (traffic).
I appreciate the tip concerning traffic around LIM in the morning, hand't considered that. British Airways hasn't been given LAN award space for our dates yet, so I don't know what times will be available.
Thanks again! I will let you guys know if I run into anything else, but these tips have helped sharpen what I had planned. Any thoughts or suggestions from other people are appreciated as well!