I got no answers to my post so, having just returned to the UK from our Mexico trip, I thought it might help others if I answered some of my own questions!
How easily can one buy small screw-in butane gas cylinders for European style alpine stoves? We’ll be staying a couple of nights in Mexico City, so have time to search out camping outlets close to the Centro Historico. Are there any good recommendations?
We had no difficulty finding sporting outlets in the Centro Historico part of Mexico City. Four minutes SW of the Zocalo are a whole pile of sports shops along Venustiano Carranzana. Marti's is OK, but Rubens is a real climbing outlet, even hiring out crampons and ice axes. (near junction with Eje Central Lazaro Cardenas)
PS: Comex paint stores sell white gas in 600ml bottles. There's one on Republica de Uruguay, close to the junction with Bolivar.
The route to Piedra Grande Hut from Coscomatepec sounds far more interesting than that from Tlachichuca – but how easily can one obtain 4WD transport from Coscomatepec, or buy any last-minute climbing gear/hill-food we might need there?
I cannot answer my own question! From Orizaba's summit the route from Coscomatepec clearly looks very scenically attractive - far more so than that from Tlachichuca. That said, the 4WD ride up from Snr Limon's through regenerating pine forest was a wonderful experience in itself. In the end we went for practicality.
How much of a nightmare is mountaineering in Mexico with virtually no Spanish language skills? We don’t plan to camp (apart from bringing basic bivvy gear) nor do we need guides on the hill, so will we find it a challenge to negotiate accommodation or hire transport?
None of our trip was a nightmare! With a Mexican Spanish phrasebook and a dozen or so hours listening to a "Teach Yourself Spanish" CD in the car every day to work beforehand, we managed perfectly well. Even without that edge, we'd have coped fine.
We’d thought of finding a hotel somewhere like Puebla to make as a base to leave extra gear for a few days whilst travelling out to the various volcanoes. (rather than MC) Does this sound like a good plan? Alternative suggestions most welcome!
In the end we found it most practical to use one hotel in the historic centre of Mexico City, returning there every few days from our trips out to Toluca and Ixta. We used the rather posh Hotel Catedral on Donceles (they were happy to store bags for us), but the nearby Hostal Catedral also served the purpose just as well. Becuase we chose not to climb Malinche, we saw no reason to base ourselves in Puebla. Instead we chose Cordoba as a base for Orizaba and then for a subsequent rafting/biking trips in the state of Veracruz.
What recommendations would fellow SP readers make for biking and hiking activities in Copper Canyon area? Are mosquitos a problem? What is the best way to get from MC to Copper Canyon/Creel, or where would be the best place to base ourselves to hire bikes for exploring?
In the end we felt Copper Canyon was just too far away to tack on to a 3 week mountaineering trip. Instead, after circumnavigating the crater rim of Orizaba, we returned to Cordoba and caught the bus to Xalapa and thence by Aztecas bus to the river-rafting centre of Jalcomulco where acccommodation and tourist trips to Class 3/4 rivers are easily available. Getting mountain bikes wasn't quite so easy here, but we managed it, and I can thoroughly recommend this verdant gorge as a great place to unwind after the hard climbs that went before. We were impressed by the safety and services ofered by this organisation: www.raftingsinlimite.com
Take insect repellant; in November this was the only place we needed it!
I hope these answers may help someone plan their own future trip!