Ensweiler,
Couple of things when it comes to the Agent configuration.
THe HTTP checkbox, is NOT a browser hook. Since this protocol is in the clear, just like FTP and other protocols the agents is able to monitor this WITHOUT hooking to the browser so this is a Protocol signature recognition/detection capability.
HTTP is done at the Network layer and independent to the applications period!
It will work no mater what browser or application is using FTP or HTTP.
Keep in mind that HTTPS is completely different for it needs to hook into the browser, since it is the application that is createing or managing the Secure SSL connection to the HTTPS Website.
The network access or other options for Applicaiton File access is monitoring a SPECIFIC executable or program as how it will Access the network or FIle System or File Access I/O. So it is VERY specific as to what that Porgram does. So for example when Chrome.exe tries to open or attach a file, that application is being monitored when it tries to acces that file. Th sam would apply to all of the other applications listed there. In some cases when it comes to Custom or user specific applications there might be a sub routine application that does the actual File reading or network access, so the monitored exectuable may not be the original application.
If this answers your question please mark as solved!
Ronak