onexiio - 2017-07-26

Hello, I have been experimenting with Veracrypt alot and have run into some issues that someone can maybe help with.

My laptop is a Lenovo T420
Specifications are here: https://support.lenovo.com/gb/en/solutions/pd015734

I have 2 Operating systems which are Win 7 (C: Drive default OS) and Win 10(D: Drive temp OS), I had abit of a trouble using the full disk encryption which started marking the parition1 \D: drive active and made the Win10 the default OS parition. Leaving the C drive parition inactive. I couldn't seem to boot into back into my Win 7 OS. had to use my recovery disk and boot into CMD to rerun a few commands for the parition C drive to working again there was also other issues aswell but after 6 hours of trying. I managed to boot back into my Win7 again and got things back to normal. But I had noticed the System reserve had unallocated space and somehow the MBR migrated into the C drive, which i can not seem to repair back into its place. The issue comes about that i cannot encrypt the system drive only the system partition as I have 2 OS's on the same parition.

On another note I also use BIOS locks for the system and the interface too. Now i know that encryption affects performance, but i want a decent security encryption for my laptop, I have been looking at different Algathrims and multiple cascade encryptions but not sure what is secure. I know AES is what goverments use but i fear backdoors are implemented, I dont trust bitlocker either. Eitherway I want to use a 3 way cascade encryption and a 3-pass wipe mode, maybe more.

So for my questions stand.

I want to get the best performance, but with also the best security also. So I'm looking to have inbetween the middle

Can i use a Full Disk Encryption or is a System Parition Encryption secure enough and are their any performance issues with this?
Does a multple cascade encryption affect performance aswell as a wipe mode?
What would be the best setup for this situation?
If the HDD fails, can i get this data back? What sort of backup can i use and can i encrypt this data to?
Does a decoy OS only allow a certain small amount of space?

I have been messing about encryption and decryption the disk and paritions to see whats the best i can get, But i fear the more i do this the more chance the HDD will fail.