In reply to Kid Spatula:
Is the mer de glace balcony trail navigable? I think some of it maybe got wiped out, but as basically an extension to the couvercle approach it's an excellent route.
To the op: I've not done that particular walk, though I've used the Skyway lift to get to Torino from Chamonix and certainly late in the season seen some fairly crevassed terrain.
Could you teach crevasse rescue techniques to your group? You could go through rigging a pulley system just using a tree or something as an anchor and dragging each other along the ground in the UK. Then when you're in Cham practice on a sensible bit of glacier.
Remember that if you do the walk to the Torino you'll be on a wet glacier so everyone needs to be confident making an anchor with an axe.
Also consider that if you did go in a crevasse, would your group be able to keep a cool head and pull you out?
If they physically can't haul you, would they know what to do, e.g. switch to a 5:1 pulley, pad the rope to stop it cutting into the lip etc.
Ultimately it's up to you how comfortable you are with your groups knowledge/ability/experience travelling over glaciers.
Personally my choice for an inexperienced group would probably be something like a night at the albert premier and climb the tete blanche in the morning. It still involves glacier travel, but the easiest route up is only an 'F' and you actually get to summit something. If worried about the crevasse aspect go with Kid Spatulas suggestion. Sitting on the terrace at the couvercle looking out over the mer de glace and leschaux with a beer is a fantastic place to be. By french standards it's a really nice hut too.