Question:I am wondering how easy to set up ?
Answer:Easy is very relative to who's asking. These are wired cams so you'll have to run that wire. If you are comfortable running 1 wire (included) to each cam, and mounting cams securely, then yes, it's "easy to set up". I have this very same system (8 cam version) and it works extremely well. While it is true that the "app" has many limitations, this system is designed primarily as a self contained surveillance system. This means that I can set it for all cameras to record 24/7. Whenever I need to check on what happened during the last month (longer at lower res settings and/or motion only recordings), I can simply go to the date/time and see everything recorded. This is done from the system, NOT on the app. When used in this way, this system is absolutely amazing at this price. Period

Question:It says it records audio but in another question somebody said no it doesn't record audio, it does record audio or not?
Answer:Yes, this system does record sound... but only on a single camera. All cameras have microphones, but the system can only record sound from one of them at a time. You MUST select which camera you want to record sound, ahead of time. ANYone who says differently, hasn't learned how to setup/use the system properly. I have this system. It works REALLY well.

Question:Can you use a wireless mouse with this system?
Answer:Yes you can, plug the mouse receiver in backup of unit and your good to go.

Question:How do i contact customer support your water proof cables are made wrong. I cant believe you dont know how to make cables
Answer:You are an expert at waterproof cables, but can't figure out how to get customer support? 

Question:How loud is the fan?
Answer:Not loud at all

Question:Can system connect to my wireless internet? Can system work locally without internet?
Answer:There are two types. The wired and the wireless camera. Only the wireless cameras camera can connect to your WiFi. The wired cameras cannot.
In terms of working without internet I've not tested that but i doubt if it will work.

Question:How long are the ethernet cables that come in the kit? Can longer cables be used if necessary?
Answer:This kit comes with 60 foot cables (4).
Yes, you can use longer cables.