Hello Yang-Rui-Jia,
Yes, you can use MATLAB to plot the data recorded by your Shake via RSUDP. You should be able to read the files using the information in this topic: Matlab question and then plot them out similarly to this: Live Seismic Traffic Monitoring with ThingSpeak, MATLAB, and Raspberry Shake » Hans on IoT - MATLAB & Simulink
Regarding your second query, you can convert counts to Velocity/Displacement/Acceleration by removing the response (that you can download from here: https://data.raspberryshake.org/fdsnws/station/1/query?level=resp&network=AM&station=R7FD6) with MATLAB, in a similar way ObsPy does it (https://data.raspberryshake.org/fdsnws/station/1/query?level=resp&network=AM&station=R7FD6). I would recommend using the MATLAB GISMO package: The GISMO Toolbox - seismic data analysis in MATLAB for all of this, as it is a great starting point for a MATLAB approach.