G770 - some questions

Hello!

I just bought an used Lenovo G770 laptop, formatted it and would like to install Windows and the drivers to make it work properly. I would like to install only the necessary drivers (so there will be no exclamation marks in the Device Manager). I want to have it as lightweight as possible, no unnecesary software. And so I have some questions about the drivers and software I found at the Lenovo site (for G770 model):

Do I have to install the "BIOS Update" and flash the BIOS? What will I gain by doing that? If it's not necessary I'd rather not do it.

What is "Realtek USB 2.0 Reader Driver"? Driver for multimedia cards or a USB 2.0 driver?

What is "Intel Rapid storage Technology"? Do I have to install this, what is it for?

What is "Intel Management Engine Interface Driver"? Do I have to install this, what is it for?

What is "Lenovo Energy Management Software"? Do I have to install this, what is it for?

Which one of the three Wireless drivers do I have to install, "Wireless Network Adapter", "Intel Wireless WiFi Link Driver", "Intel EchoPeak WiMAX Driver" or all the three maybe?

Now about the software offered on that site:

PowerDVD 10 BD - that's just a DVD player, right?

CSUP - what is this? Do I need it?

Lenovo DirectShare - what is this? Do I need it?

Lenovo EE Boot Optimizer & Service Modify For EE - what is this and how does it work? Do I need it?

User Guide Program - what is this really?

McAfee & McAfee Patch - that's just an optional AV program, right?

Lenovo Onekey Recovery - I've read about that. You press one button and the laptop returns back to the initial state. Is it

possible to set your own initial state? So that if I use that button it will return to a custom state that I created before and suits my needs?

Any help is greatly appreciated! Thank you!