Network drivers have to be manually installed if, of course, the computer can't connect to any networks so it can automatically download drivers. Install LAN or WiFi, whichever you use.
Base (X99) chipset drivers are necessary. Intel IME isn't strictly necessary, I wouldn't install it unless something else complains about it being absent.
Windows "WQHL" drivers/versions have to go through a validation process (which takes time) to ensure the drivers are "fully" debugged, etc. So Windows drivers are always slightly outdated (and never beta), but they (almost) always work.
The latest-and-greatest driver versions can always be downloaded directly from Intel, ASMedia, Realtek, etc. The ASUS sites of often outdated and messy. But the differences between driver versions are typically insignificant in terms of real-performance (unless they state otherwise). Many driver revisions are in fact only minor version-control features or documentation or organizational updates, not the actual code itself. But, all other things being equal, newer is usually better.
ASUS embellishes the onboard audio with extra software you don't really need to install if you're happy with basic (ALC1150) audio. You don't even need to install the ALC1150 if you're using a dedicated audio card/device instead of onboard audio.
You don't really need to install any ASMedia drivers if you're not connecting anything to ASMedia-controlled SATA ports or USB ports.
No need to install Bluetooth or iGPU or whatever other features might be clumped into the download pile (especially when no such hardware is even present). Windows will prompt you to install drivers whenever you install new GPU or BT (or whatever) hardware.
The ASUS utilities are very hit or miss. I usually install *everything* on a clean WinOS, try it out, play with it - useless cruft can be discarded immediately, somewhat useful cruft takes a few days longer to identify, whatever's left (which tends be very little, if anything, lol) is worth keeping.
AURA controls LED lighting, colours, effects, etc. Don't need it unless your have the LEDs and wanna look pretty.
GameFirst is basically a tool to segment and prioritize network traffic. So you can download torrents while keeping good pings in your fps. Don't need it.
Stuff like DIP5, AI Suite, Extreme Tuning, Fan Xpert are for configuring and controlling overclocks, hardware/temp monitoring, etc. They can be used to automatically "smart" configure everything for you. Good for quick-and-easy testing and good to use as a reference "baseline". But then they're no longer needed and can be uninstalled. Better overclocking with more options and finer controls can be user-configured directly in BIOS, and they don't require installed (sometimes buggy or problematic) software to be running all the time.
KeyBot is indeed a keyboard macro utility. You don't need it unless you really want to use macros and you utterly lack macro functions on your keyboard.
ROG GPU-Z is just GPU-Z with a ROG-branded skin.
RAMDisk and RAMCache can be useful, if you have tons of unused RAM.
If your mobo came with "free" antivirus or game codes or whatever then you might as well use them up before they expire.
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