Hi Donjoz,
Our building is also currently looking at using software for this purpose.
Options we have looked at are buildinglink.com.au, mybos.com.au, buildingmanager.com.au and cybercommunity.com.au
The first and second of these have been highly recommended to us by existing users of the software.
We use a professional Strata Manager who uses a web based software package that we have access to, but it does not do the items you have stated above except the storage of documents. We are planning for the OC to directly pay for the software and then have our Building Manager / Strata Manager / EC / owners / residents use it, so that way the OC keeps control rather than being beholden to our Strata Manager for ongoing access.
Hope this helps.