two stages campaign idea, feedback wanted

[THM]

Hi all

New here and all, have this idea and want to get feedback.

my idea is a world with 2 parts, in the first part, the world the campaign takes place in is still new and magic run wild, the characters will have very fast progression, high magical rewards, and will end up beating a demon who took place creating the world, in the process, they will each bring an army from different races and zones of the world.
This part will be only 1/4 of the campaign (fast progression, high magical rewards) and at the end, the characters will sit down (well, the players) and have to set some guide lines (like to which race to give the treasure of the demon for keeping since it contains dangerous items, how to deal with people who wield cosmic energies (mages and such, if to let them roam free, or to create towers for formalize teaching) and so on.
This chapter end, and second part starts, the players create new PCs, and play in the same world, but 1000 years ahead (or less cliche time gap) now the choices they made, effect the world, the old PCs became lesser gods, but their rules are corrupting with time, and the world is again on the edge of chaos.

The party now try to save the world from gods going mad, effected somehow by a timeless stranger who advise the gods.

at the end of this cycle, the party will leave the world broken after a huge war.

my main concerns -
1. Wont the player kinda be mad at starting over at the middle? should I discuss it with them before?

2. my friends tend to go for usual roles - got the "brainless knight" a player that end up playing paladins/knights/whatever with a simplistic code of honor, who tend to be manipulated too easily on one hand, and to stand his ground if he thinks something is wrong (in other word, can't give him a moral choice)
second one is playing the advisor - he is more then happy not to interact with any NPC...ever, just tell the other players (not even PCs) what he think should be done. the guy is also a great story writer and usually get twist too soon
and the third tend to build evil character, or at least chaotic, tried running Starwars one, he played a jedi that ended up splitting the order.
so my player base is a tad problematic. Maybe I should build a campaign to fit them better?

so, what's your feedback?

sorry for the messy post

[Atarax]

Just some quick ideas in rambling, half asleep English- maybe have them play descendants of the first heroes. Or maybe the epilogue to the first part is that the original heroes found some sort of order or settlement. When the players pick up centuries later, you can have them find bits and pieces of what became of the first heroes. Maybe these bits of history will provide necessary clues to deal with this evil once again.

If they're gonna be mad about abondoning the first characters, you could have the new characters' quest be to find the original heroes. Perhaps the historical clues lead them to discover that the original heroes have been magically sleeping until the days when the evil returns to the world. Once they find the originals, you could the two groups split up to complete two objectives to conquer this evil once and for all. They could complete one set's quest then switch to the second. Or maybe they could just switch back to the originals for the last part of the adventure when they finally fulfill their destiny and defeat the evil once and for all. If the newer set of heroes only play a brief role in this campaign, you could easily base a second campaign around them. Then again, you could make the first heroes role brief, leave their history a mystery, then go back for a second campaign about what exactly happened to them. You get the idea..sequels and prequels

[THM]

Thanks Atarax