Exploiters or ‘Hackers’ can see anything sent to the client, whether it is through a remote function parameters or even parameters in code-embedded functions.
To answer the point, if that code was in a client script they would be able to view it.
If you are asking whether or not an exploiter can see someone else’s communications to/from the server, then no, not to my knowledge is there any way for them to monitor traffic of others. They can see anything the server and their own scripts are communicating as others have said though.
No, most likely not.
Hackers can’t see passed parameters through functions in your scripts but they might be able to see parameters from RemoteEvents and RemoteFunctions by injecting a script with .OnClientEvent or .OnClientInvoke(Do remember that hackers can only inject localscripts unless FilteringEnabled is off).