Well, IM (Limited) Exp - DS certainly didn't 'need weaning' other than that he'd been fed milk for six months and he needed to start eating food to a) get used to it and b) build up iron stocks.
IIRC, 16 weeks is a growth spurt, so just feed, feed, feed - they won't over eat!
I also had a period that I called 'the witching hour' which I've since read about on here, which started about the same time. From 5 till 7 pm EVERY day was a ruddy nightmare, with lots of grumps from DS and me climbing the wall by the time DH got home. At least this time around I'll know it doesn't last long.... comparitively!
I didn't have any routine - I was DS led for everything, mainly as I didn't have a clue what I was doing, but DS let me know, and it made life less stressful. So if he cried, and I thought there was a possibility of hunger, he got the boob. My sister (when I phoned saying "but he can't still be hungry / be hungry again"...) if he cries, shove a boob in, if he eats, he's hungry, if he doesn't, he's not. It was always for the food!
I'll do the same again this time, DS permitting of course!
So, rambling aside, I think its just a growth spurt and would feed on demand (if you do GF routines, 'fraid you'll have to wait for Diege as I have no clue how that works). And it will settle down, and won't last all the way to 6 months! don't quote me on that will you