Having a new jib made for the franken 18. I was leaning toward a full batten jib but the sail maker seems to see it as a compromise, soft sail offering better performance in lighter wind conditions.
What do you guys think, soft or hard?

Battens will lengthen the life of your sail.

extend it by how much? 15% 20%?

why not get partial/angled ones so you can furl? (i would give up 20% of its life to have the ability to furl (for anchoring) and or in case i am overpowered ... in a heart beat

I agree Andrew, the ability to furl outways full battens. You also don't have the jib getting caught up against the mast. Do you remember the H-16 days?

Self tacking?
Over Lap? If so how much?
Used for racing or fun sailing?

Yes
No overlap
Racing and fun

Typically full length battens are used on self tacking jibs to try to fill the entire front triangle between mast and forestay; filling in even the leech curve that would normally be cut into a jib to (re)gain even that small amount of area. As already mentioned, an extra benefit is that the sail lasts longer as the battens prevent most wear and tear from the sail beating itself up in the breeze. The downside is that you cannot use a roller furler and the sail is less shape sensitive in light air as already mentioned.

Pelican strikers allow an even bigger gain in area by extending the luff length down to a pole from the front beam to below the bridle - if you already have a spinnaker pole then you get more bang for your bucks as it serves double duty. A large window in the jib gets to be pretty important otherwise you cannot see what is on the other side of the boat. The attempt to gain more sail area inside that triangle is to try to regain some of the area lost from using an overlapping jib. However another gain from that move is a much tidier tramp and faster, more consistent good tacks with a self tacker.

The gain in sail area using full length battens is very small but the gain from using the pelican striker is significant and trying to use a furler with a pelican striker would be problematic. So if you want to use a furler you would end up with a smaller jib. You just have to decide for yourself which of these considerations carry the most weight for you in your situation.

Excellent synopsis Mike!

Dave