1) Is it possible to redirect our user to Authorize.net web page form where they can enter CC information. We do not want to use our own page for such information.

You can create ARB on the merchant account.

2) Same question for AIM

Thru merchant account or use SIM or DPM

3) If users go trough AIM can I get some kind of an ID which to be used for creating an ARB subscription for the same user

If there is a  success transaction, you can search on the transaction Detail to create ARB.

4) If users supply their CC info trough Authorize.net web page is it possible for them to update that info later?

There is the ARBUpdateSubscription method

or use CIM

http://community.developer.authorize.net/t5/The-Authorize-Net-Developer-Blog/Choosing-a-Recurring-Bi...