It depends. It’s ok for a buyer to send links to websites to show what he’s looking for. Let’s say you’re a web designer, and they want a site that has the same style as another website, it’s totally fine for them to provide you with links for inspiration. With that being said, making exact copies or stealing a layout/design that belongs to someone else may be a violation of copyright law. If the buyer asks you to make something identical overall, I’d be very skeptical.
Teamviewer is an acceptable tool to perform your work on Fiverr, if it is needed to complete the task. As with all tools and third-party services, they should only be used when it’s necessary to complete the work. If a gig requires you to install software on their device, that makes it necessary, and ok.
Well, there’s bunch of words. Usually you’ll get a red warning next to your message whenever you include a flagged word, but not always. The names of some social networks and services like VoIP-software, payment providers, the word “review” etc. will cause your message to be flagged.
If you read the terms of service, and always follow the guidelines, you should be ok!