Assuming that you are running a Shimano set up, the lever is exactly what Trever was refering to. With the clutch engaged, the derailleur is hard to move, and disengaged is it easy. Always disengage it when removing the rear wheel.
I use a Sunrace 11-42 currently on my Lycan, but believe that the Lycan originally came with an 11-36 cassette.
Also by memory a 15t front sprocket size was standard then, but has now changed to a 16t.
I still run a 15t front sprocket as it seems to work very well for my needs.
I'll check the chain length a little later, but again by memory with my current 'non standard' set up, I think that it is 107 links.
If you happen to change to my set up, you will require a fractionally longer 'B' screw for the derailleur.
Is there a reason that you can't check what the bike already has, or has it already been altered from OE spec?
This is the current set up.