So I am concidering to become a werewolf, but I wonder what advantages and disadvantages it gives.
1: How is my human form affected(healing, resists, weaknesses etc)?
2: Do I have to transform regulary/Can I stay in human form without transforming forever?
3: Can I shout in werewolf form?
4: I expect that you can't cast spells so is there a way of healing in werewolf form?

In Bloodmoon you don't get a bounty for crimes made in werewolf form so I assume that carries over.

Please do not post how one can become a werewolf if it is tied to a quest. If there is a location were I can fight werewolves and become infected please put it in, but in spoiler clams so others that might not want to know do not get spoiled.

1 other then being immune to diseases and not being well rested no
2 no you can transform at will once a day when ever you want
3 you cant shout but you can howl/roar idk what to call it...it causes fear
4 after killing someone you can feed on their carcass

Ok, thanks

Not Sure...

from what i heard, you cannot heal while in werewolf form, that means no eating, using potions and obviously using healing spells.
this could be a possibility why they put in health regeneration.

i could be wrong though, but it would make sense since being in that form your DPS goes up like crazy.

You can only attack, feed on people, roar and sprint. All the other menus and options are locked.

feeding on people heals your health, but also raises/resets the bloodlust time, and you wont turn back into a human until you ran out of bloodlust which is about 120-180 seconds if i remember correct.
but, if your impatient u can still press T and wait 1 hour to transform back

I'll post what the guide says to help you out, if I'm allowed to.

I'll wait for approval first though.

Well, if it is spoilerfree it okay. If not please make it a bit vague and put it in spoiler clams.

lycanthropy is cool!
as people have said:
change at will once a day
roar/howl causes same effect as Fear spell
eating dead people recovers health but also increases bloodlust time (time required for auto change back to happen)
immunity to diseases in both forms
health gain in both forms
beast form can, sprint, walk, jump and also has a dash attack. primary attacks can be held down to perform multi slash combo

negatives
most people seing you in beast form will either attack or run
when you change back your naked appart from loincloth
no access to any inventory items/skills/magic whilst in beast form
silver weapons will harm you more
unable to gain "well rested" perks after sleeping

there is a cure; but once used there is no going to back to either being a werewolf or a vampire

Something that nobody mentioned: Your endurance gets a boost, and it recharges really fast. You can pretty much sprint forever because of it.

There really are no negatives, unless the bonuses you get from sleeping are really good.

I'm going to mark the answers as Spoilers just to be safe. I will NOT spoil Quest related information. I will just safely answer what you asked for about Werewolf powers and abilities. Understand that there is even more information about them. Hope it helps.

Quick extra question: Does werewolves age, or have a slowed aging prosses? Or do they age normally?