Well, I didn't pull all JF, but I pulled enough to play a good JF pure army.

As for your army, from what I saw today and yesterday, I'd trade the two Gun Nests for a Slyph BA (30pts) and a Sniper Team (20pts) for a total of 450 points. Unless someone had blocking and a JF mech, the best plan for taking on a Kelswa is arty or stay away from it. The Sniper Team gives you an infiltrator, and one that can cover a good chunk of the battlefield. The Slyphs can be so deadly and can help in the base-n-break or VC3 rush. Also, using Pulse the JF Slyph can hit an Elite unit for a total of 6 damage (and one click of heat) in a turn. (Pulse plus Zell).