I quite like your list, it is a very good starting point that we can work off, so here is a run down on what I see:
H.Q.
Many people will tell you that an Archon on a jetbike is better, and then a dracon with a retinue, but in this list I think the archon/incubi combo is good. As stated above the Archon needs a splinter pistol, and the whole squad must be mounted on a raider to come out of the WWP. Some extra wargear and stuff would be cool for the Archon too, but its not really a priority.
The Heamy is quite a good choice for the WWP carrying capabilities. I will tell you how you should join him to a squad later.
ELITES
First things first- get another raider! if you dont have the model I strongly advise getting another one. Also I think they should be armed with a DL and given a horrorfex, except maybe one, which you can give a dessie- just my thoughts.
Ok, moving on- make the wych squads 9 models each. This is a better number than 8, and no worse than 10. It will mean 3 of them must die to force a morale check instead of just 2. I think your list lacks tank busting, and squads like these are a good area to pick this up. Give your squads blasters as often as you can. They are cheap for a 'just in case' and can be used to soften up a unit before you charge. Put as many of the wyches on raiders as you can 9remembering your HQ takes precedence).
TROOPS
The sniper squad is good, keep it as it is. Use them to defend the WWP and for giving cover fire to your carrier troops.
Your carrier units (at least two) should be 14 or 15 models strong at least. In your case you could get away with one squad of fifteen and one squad of ten, so lets work off this- give the sybarite to the squad with fifteen so he has more chance of survival. Give the Heamy to the squad of ten, as he can always leave it and run to the other squad if he has to. And yes, do replace the shredder with a blaster, and give the other squad another blaster too if you can.
FAST ATTACK
I think that four reavers can work, although admittedly five is better. They are expensive though and often dont last long. hey are a bit of a pointsink and not generaly my first choice. I would preffer if you put in another Talos instead, but if you dont have another one then the bikes are not bad. Just use them as anti tank, speeding around to find weak rear armour.
HEAVY SUPPORT
The Ravager is good as is- DO NOT CHANGE THE WEAPONS!!! A three dissie ravager is awsome for taking out squads at a time, especialy adaint SMurfs.
As for the Talos, it is a lot better to have 2 of them working together to make them more reliable. You dont want to charge some termies or squads with power weapons or something, roll one attack and be pummeled in return. With two you should average about 7 attacks a turn, which will usualy see you safe.
Overall I think it is a pretty steady list. Good job.