Your problem with WiFi looks more like a hardware failure than software/driver issue ... yes ... you should start your troubleshooting with drivers because wrong driver can cause many issues - especially if you use driver which is not offered by vendor of the notebook - in your case ASUS. Experimenting with drivers not recommended by vendor can be performed only after you fix your problem with radio - simply: Make it work purely as described in original documentation to simply verify if you're facing to some bigger problem or not. Simply follow these steps:
1. Download and create some Linux Live USB Boot Flash (or CD from ISO if you have CD-ROM only and doesn't have appropriate USB Flash Disk). I recommend some version of Live Ubuntu for this purposes - this can be done using actual OS or you can prepare it on different machine.
2. Restart your laptop and boot your Linux Live distribution and wait until it starts - in case of Ubuntu your laptop will start and Linux desktop will appear on the screen. Now you should be able to check your WiFi - all drivers (and especially for WiFi) are already included in your Live Linux. If you will see the WiFi card and if you will be able to connect your WiFi network, check if the problem with radio and sensitivity still persists. If not, the problem is somewhere else because in case of problem with Win driver, this Linux driver cannot have the same problem. Just only in case that your wireless interface won't be visible in Linux Live the problem can be with missing driver on Linux Live - very rare.
3. In case that Live Linux will work without any problems, try to restore your notebook to factory default from installation image - should be on your HDD if you didn't do re-partitioning (only if you bought your notebook with OEM Windows OS pre-installed). This image contains all necessary drivers and tools which can be pretty old but still must work (you can update drivers, etc. by actual versions from support pages maintained by ASUS but before that please check if your WiFi works or not). In case that your problem will persist, it will be probably related to hardware (wireless card, antena, etc.).
4. Check cables connected to your WiFi module... In case that it won't work, replace the module by different one or try this module in different notebook. There is a possibility that the output of RX/TX part is broken so everything is working, but radio part of your WiFi module doesn't work.
From my point of view: I think that this is HW failure... Maybe just crappy WiFi module, or something like this, but this is strange behavior... Keep focus on testing by proposed Live Linux OS - it's the easiest way how to check it. WISH YOU THE BEST!