help! Stiffening/reinforcing leather satchel

[Kolfinna]

Hi everyone! 

I think I may have worked myself into a corner and now I'm stuck in paralysis by analysis. I'm making a satchel from Hermann Oak 1881 and while the color and feel are beautiful, the leather behaves like a chrome tan in that it has a soft temper. 

So: being one who learns as they go, I decided to line it with more of the same leather. It wasn't looking like the bag would stand on its own, so I got some 1mm reinforcement from RM Leather Supply, laminated the front, back, and sides, but left the flap/cover unglued for now. 

Here's where I am stuck: do I commit and fully laminate the entire bag? Or save on materials and weight by only laminating the front, back, and sides? I currently have it cut to support full lamination, but I worry the bag will be too stiff in all the wrong places. However, if I cut out the bag reinforcement, then I can't go back. 

What would you recommend? The satchel is 16" x 10" x 5" (ish). Maybe a super soft/floppy lid is okay??

Thanks in advance!

[HaloJones]

It’s personal choice, but I would not line the flap.

[toxo]

Stiffen the "spine" under the handle and the two side gussets.