Your paraphrased introduction sounds exactly like a summary for a convention game. If you are to planning to start a campaign, I would strongly urge to not begin this way. But if it is a one-shot or a one-module-only game you are after, then you are perfectly fine. I agree with Jdvn1 about giving the characters free reign in making their decisions. If you really are starting a campaign, you will need to pick or build a setting (or at least a local area) and a handful of modules to tie into the surroundings.
For instance, start your guys off in Hommlet, but with the villiage filled with immigrants from the abandoned mining town. To the south is the mine, to the east a moathouse, to the west forest with with a deep crevasse (sunless citadel), and to the north a keep and orc country (keep on the borderlands). In general you won't need higher level modules tied in yet, but it's good to keep an eye on what you may want to include later. That way you can lay the ground work for them and maybe a little foreshadowing.
I don't believe you want to force players in one direction, but they will need to be presented with alternatives so they do not become complacent either. This means an event-based approach rather than a geographical one (as outlined above). Seeing as your main adventure is the mines, spread rumors about the sickness and the rate at which people are dying and being displaced. Be sure to spread rumors for the other adventures too, though. Pay particular attention to the consequences your events will have if the PC's do not become involved. Hommlet is likely to have a food shortage problem and if winter is coming fast many might starve because of it. As the PC's cannot solve every problem, be careful not to overwhelm them. But also understand your new players will likely need to see the world go awry before realizing they are the heroes needed to save it.
It sounds like you need a hook to bring the party together (and maybe keep them together after they have accomplished their first mission). I play in a game where we started off as militia soldiers defending a tower. Others include: starting in a prison as the prisoners, all being invited to a funeral (or wedding, etc), and hired individually by a person in need. There are plenty of ways. I even started a game off with the party split in half both working in pairs to kill the same target, but for different reasons. Neither knew of the others existence, but the game was played openly so each had player knowledge of the other PCs. (the target managed to escaped, but not before each realized they could only defeat him together). What I do not suggest is the old "you're in a tavern, and you all know each other" opening, but it's your decision. These suggestions are really only the tip of the iceberg. I'm sure plenty of others could be gleaned from the starting-a-new-campaign threads.
Good luck.