Hi FRG,
1. The Synchronized SE 1 has a light version of the Synchron Concert D piano included, which alone needs ~33 GB. Also Solo Violin 2 and Solo Cello 2 were added. The Vol 1 Plus package adds some articulation to the instruments of Vol 1 (araound 12 GB: https://www.vsl.co.at/en/Synchronized_Special_Edition_Bundle/Synchronized_Special_Edition_Vol1_Plus#!Product_Info)
2. The Synchron Player has not the same matrix structure as the VI player has, so there are no X-Y axis. It uses a tree structure, which is also configurable and you can choose to use KS, Program change, CC, and more for switching articulations.
3. Yes, you can disable the reverb and use the dry sound.
Best, Ben