Your iPad is jail broken, which opens up a whole lot of reasons why you are unable to install or uninstall apps. However, I've never seen it where the restrictions line is gone entirely from the Settings app.
What version of iPad do you have and what iOS version is it running? In addition to the four Cydia tweaks that show in your screenshot, what other tweaks do you have installed?
Knowing the answer to those questions may help us help you. Thanks in advance.
P.S. And, since your iPad is jail broken, I've taken the liberty of moving your post over to the jail breaking section, where more people, who are familiar with jail breaking, can see it. Thanks for your understanding.