Endpoint Management Software Resources

All depends on what is slow? I have never had any Trend Product perform negatively on the endpoint with performance. I use Apex One as a service and it is also fast. So maybe if you are running it locally? Not sure if I can fully answer your question without more details.

It seems you're looking for a content filtering solution specifically. Many products do that - sometimes features of your firewall (there may be a license or subscription to purchase), or a software solution that resides at the endpoints (it would be very important then to have it centrally managed). I prefer at the endpoint, so the policies travel with the endpoint and are in effect even outside the corporate network. I don't think this is the proper forum to make specific solution recommendations, but at the moment we're using Avast CloudCare, which has a category based content filter and it internet portal managed. It works well alongside MalwareBytes (Endpoint Protection in our case).

No, MB catches sites that have malware on it and will block the site.

Another security layer, such as a perimeter firewall, can be used to address the web filtering and deter unwanted incoming traffic.