Using the arcane system of gear inches may help you get to the setup you want. Gear inches are calculated by front sprocket / back sprocket * tire diameter in inches.
At the low end I run a 24front and 32rear and my 700x35 tires are about 27.5" diameter, yielding 20.6 gear inches. I imagine that opinions differ, but I would say something around 20 inches for your low gear is a good credible setup for a touring bike. Your current setup is about 21". If you make the suggested swap to a 24 chainring that puts you at 19.4". Swapping to a 22 puts you at 17.8".
Carrying the arithmetic a step further, at a 60rpm cadence, your current setup will climb at a brisk 3.75mph. If you get the gearing down to that 17.8" you will climb at a more leisurely but steady 3.2mph at 60 cadence. I've heard the argument that you can walk that speed, but I don't see strolling that clip on a steep uphill with the additional 10lbs of force it will take to keep your bike moving.
Changing gears here (ha, ha), if you have an M592 Deore Shadow, Shimano rates it for a maximum front difference of 22teeth and a total difference of 45teeth. If you follow their guidelines, you are at spec for the front (48-26=22) and for the entire system ( (48-26)+(34-11)=45 ). It would surprise me if you can't cheat on the tooth count a little and I'll let someone else weigh in on that. Digging into the Shimano table further (
http://productinfo.shimano.com/#/spec/2.8/MTB/Rear%20Derailleur), I see only the RD-M8000-SGS is rated for more total capacity at 47teeth, so your deraileur is no wimp on this front.
I used the setup described (20.6") on the TA and started with a weight close to yours. I didn't use the absolute bottom gears except for a handful of steep climbs in Missouri and appalachia. Wouldn't have minded another gear-inch lower for those.