Am I able to do shallow DoF with RX100?

IMO, for your work, you need a bigger sensor than the rx100 for reliable portrait shallow dof.

http://en.wikipedia.org/wiki/Image_sensor_format#Table_of_sensor_formats_and_sizes

I use sensor area, square mm to more accurately compare them; sensor technicalities differ also.

rx100 has what I call 'type 1', it is slightly smaller than a 1" sensor. sensor area 116 square mm

canon G1X has 1.5" sensor, you might think only 1/3 bigger, but sensor area is 262 square mm, more than double the area.

so, the word pocketable needs to be refined, because any camera with a bigger sensor will not be pants pocketable like the rx100 truly is. I mentioned the Canon G1X because it is relatively small, I would say jacket pocketable.

Elliott