There are lots of potential benefits for engineers who understand patent law and who take some time to understand what competitors are trying to protect. However, the question focused on problems associated with using this site.
Two potential legal problems are (1) being charged with willful infringement (or inducing infringement); and (2) beign charged with inequitable conduct. It is my view that neither of these are likely although some precautions might be needed to ensure that you do not run into trouble.
Willful Infringement: Patent infringement is often thought of as a strict liability tort. It does not matter whether you intended to infringe or even knew that a patent system exists. Rather, if you are practicing someone else's patented invention then you are an infringer. Knowledge and intent come in a few ways. First, if a jury knows that you might have copied then they may be more likely to judge you as an infringer (even though copying is irrelevant to the law on that issue). Second, once you are judged to be an infringer the court can treble (triple) the damages if the infringement was "willful." Knowledge of the patent is a critical element of proving infringement. Third, sometimes parties are sued for inducing infringement -- i.e., encouraging someone else to infringe. If you are liable for inducement then you will be jointly liable with the actual infringer. Inducement requires proof that you knew of the patent and encouraged someone to infringe it.
Now, in this discussion of infringement, I have been using the pronoun "you." The question was about engineers, and engineers are almost never accused of patent infringement. Rather, it is some company that they work for who is accused. Usually, the knowledge of a single engineer will not be imputed onto the company itself. That changes if the engineer is somehow in management or if the information is shared with the group.
The way to protect against willful infringement is not to bury your head in the sand. Instead, when you identify a patent that your company may be infringing, you should identify the patent and notify your counsel. In most cases the attorneys will be able to provide a fairly simple course of action that avoids the threat of treble damages. In any event, the trebling of damages is normally 5-10 years down the line if ever.
Inequitable Conduct: I suspect that many of the engineers looking at this site are involved with obtaining their own patents or are perhaps leading their company's patent efforts. Anyone involved with the filing of patent applications (including the inventors) owes a legal duty of candor to the USPTO. In addition to telling the truth, this duty also requires that you inform the USPTO of any information that you have that is somehow material to the prosecution of the patent. Most often, this obligation is satisfied by submitting copies of all the relevant prior art that you know about to the USPTO. The average patent applicant submits about 10 documents of this type to the USPTO per patent application. Besides the duty of candor, it turns out to be a good thing to submit prior art to the USPTO. Every quantitative study that I've seen on the topic finds that patents tend to be more valuable when more prior art is cited by the applicant. This shows the world that you care about the invention.
Now, the USPTO usually does not catch anyone failing the duty of candor. Where it comes up is later in litigation when you are trying to save your company by enforcing the patent. If it turns out that you failed to submit important material, the patent can be held unenforceable. The best course of action here is very straighforward - when you see information on this site that is somewhat close to a patent you are working on, then you should submit that information to the USPTO - easy.