I was wondering is it possible to run in a 24 GB configuration and benefit from X.M.P. and dual channel mode if the RAMs configurations are 2 x 8 GB + 2 x 4 GB. The RAM that I'm plannig to buy are all Corsair Vengeance Pros 1600MHz.
Yes. Just look at the manual of the motherboard to see where you put your sticks, but I think 16 Gigabytes of RAM is enough even for hardcore video editing because It doesn't affect your FPS unless you have only 4 gigabytes.
Yes if you put same size rams into same colored sockets on motherboard it will work in dual channel and xmp should work too. But if possible try to match all other parameters too (speed and timings).
Yes. Just look at the manual of the motherboard to see where you put your sticks, but I think 16 Gigabytes of RAM is enough even for hardcore video editing because It doesn't affect your FPS unless you have only 4 gigabytes.