Anonymous wrote:

Assuming that you have no intention of doing this, and this is just an exercise in understanding sail balance on the mast, here are a few thoughts

What you would have sounds more like a fully battened Gaff Rig rather than a Junk Rig (Fully Battened Lug Sail).  As such, you'd probably need two halyards, a throat halyard and a peak halyard. You'd need these because a single halyard from the middle of the yard (now Gaff), would have a terrible angle to the mast.  Getting the Junk rig to set well relies in part on using a yard angle that puts the halyard at a very small angle to the mast.  Steep yard angles with low balance and low yard angle with more balance.  But, with no balance, the halyard is always trying to pull the sail forward of the mast (thus the two halyards on the Gaff Rig).  I suppose a modern solution would be something like BattCars, expensive and certainly a step away from the simplicity of the Junk Rig.  You'd also increase the loading on the sheets with no balance of the sail in front of the mast.

I'm sure there's a bunch more to consider,

Yes, this is the type of information I'm looking for!  I have 0 intention, desire, or anything else related to constructing this.  I'm just wanting to understand the mechanics of why the Junk rig is the way it is.  Thank you for the details.

You could probably do so but you'd just create entirely needless problems for yourself. So I'd call it a pointless exercise.

Does a junk rig need to extend forward of the mast? Say, have the battens attached with beads?  What issues could this raise?

I have no intention of doing this.  The question is more for understanding the function of various parts of the sail. 

TIA