Thanks a lot

Gender: Male.
Age: 24.
Status: Slim with a bit of fat.
Experience: About a year ago I went to the gym for two months and a half, then I got what I think is the iliotibial band syndrome. Now I have little or no bother about this. Also, I did some sports when I was younger, but I have had a mainly sedentary life.
I've looked for the proposed exercises (push-up, pull-up and squat) and this is what I've found:

Source: "Strength Training Anatomy" book by Frederic Delavier.
1) So it seems that the trapezius and deltoid muscles are not being worked*, is there a reason for this? Should any exercises be added?
*Lower back seems to be left aside too, but it does not look as important as the areas above.
2) I know that the squat in SimpleFit.org is not supposed to be performed with additional weight, but that's the closest image I've got... Without that extra weight (and just body weight) will the abs be worked or some sit-ups should be added to the routine?
3) What do you think about adding some cardio (like rope jumping) between the exercise days?
Thanks in advanced

PD: Sorry for my Enlgish! I'm not a native speaker.