In many workplace they always encourage junior network engineers to follow a Cisco certification path, either through the Routing and Switching path or other important technology paths such as network security and VoIP. I have been in this industry for more than a decade and I firmly believe that in order to succeed in the networking professional career one must earn relevant professional certifications.
Getting your Cisco CCNA Certification is perfectly sufficient to start with; don't be pushed into attempting your CCNP. After gaining experience in the working environment, you will have a feel for if it's relevant for you to have this next level up. If so, your experience will serve as the background you need to master your CCNP - which is quite a hard qualification to acquire - and mustn't be entered into casually.
Most network administrators and engineers are going to spend a lot more time troubleshooting than installing. That's just the way it is. And to troubleshoot effectively, you've got to know what's going on at all layers of the OSI model, not just layers 2 and 3.
As someone who's done a lot of hiring and conducted a great many job interviews, I can tell you that the ability to troubleshoot is the number one quality I look for. That's why I tell CCNA and CCNP candidates that they've got to get all the hands-on practice they can while I understand the importance of theory, the only way to develop troubleshooting ability is to work on the real deal. No simulator program
is going to teach you how to troubleshoot.