While I agree with much of what you said I would totally disagree with recommending a FRAMELESS pack and I would generally disagree with an Alice pack.A man can carry a fighting load of about 60 lbs and cover 20 miles a day Females Can carry about 35 lbs. melonsdad is completely correct most carry way too much. When it comes time to pick a rucksack look at the old Alice pack or the newer frameless one. Your tax money developed them and they work well. Also make sure you have day pack/assault pack in case you would have to drop your main one for whatever situation.
If you can't carry it you don't need it.
My 21 year old daughter uses trekking poles, I use trekking poles. Its not a matter of age, but of realizing how much they actually provide in terms of help and support for your body.My weight is 175 and I completed 4 miles with a 35 lb backpack last week. As I get older I have been using walking sticks much more. They really help taking some of the load off my legs going up hills.