Rick, I just made this trip in November. There is no refigeration in the Khumbu valley, and all the meat is transported on the backs of porters or pack animals. Once you've seen an imperfectly covered load of meat heading up a trail rich in donkey and yak dung, meat seems a lot less attractive. I'm a big meat eater at home, but I went veggie for the duration of my trek. The #1 dish in Nepal is dal bhat, which is lentil soup over rice with a side of curried vegetables. There is plenty of protein in the lentils to get you through the trip. I actually gained 3 pounds during the trek.
The hiking is not particularly hard if you are a regular hiker in the mountains, but I'd recommend doing your best to get in good physical shape. On the way up my longest day was about 7 miles, but it also involved gaining about 2500 feet largely on stairs. Many folks find the stairs hard on their knee joints, glutes and quads.
Altitude sickness is a crapshoot. I am in my 60's, a regular mountain hiker, and took Diamox starting the night before the trek in Kathmandu. I didn't have so much as a headache, but I met fitter and younger folks who had to turn around and go down. Being fit doesn't in itself grant immunity from altitude sickness. However, there does seem to be a connection with over-exertion. The fitter you are when you arrive, the less chance that hiking the usual itinerary will cause enough stress to trigger altitude sickness. Be sure to stay hydrated too.
A liter of hot water typically runs between $1 and $2.50. Prices get higher as you gain altitude. I brought along a UV pen which I used on tap water and I had no gastro-intestinal problems on the trip.
The trek to EBC is an amazing outdoor adventure, but it is not a wilderness experience. During the high season 100 people a day will be starting the trek from Lukla. The trail is quite crowded with trekkers, guides, porters, and trains of pack animals, bringing up food and drink for the trekkers. Be patient, go with the flow. The mountains are incredible, the Nepalese are very courteous hosts, and you can meet fascinating people from all over the world.