i suspect a laser disco ball concept is going to be way too power hungry, and that means it will be prohibitively massive with todays power technology.

The liquid metal armor idea isnt entirely scifi. Liquid armor already exists using non-Newtonian fluids. There are commercial products for motorcycle armor you can buy today. For Liquid metal armor, check out ferrofluid armor and the AFRL. Unfortunately, these arent worth the bang for the buck, in terms of protection versus mass compared to a traditional kinetic whipple shield.