Do I need Intel RST for trim to work?
No. TRIM is done by the OS.
Of what benefit does RST give for a non-raid system?
None. Unless you were planning on using an SSD as a cache drive.
Intel Management Engine Interface V8 What does it do? is it needed, any special requirements installing it on new system?
Intel Management Engine is related to remote access functions. If you're not remotely accessing your PC, you can ignore this. More info at https://en.wikipedia.org/wiki/Intel_Act ... Technology
Can applications/games be installed to the 1TB hard drive rather than the SSD? any special method?
Yes, just make sure you change the install directory.