Workitem customization capabilities

Hi,
I am looking for following capabilities of workitem customization in RTC that will allow me to tailor part of the RTC process to System Engineering process that I am currently practicing.
1)Creating custom attributes ( non-editable ) derived from other attributes (multiples) of same workitem
2)Creating custom attributes (non-editable) derived from attributes (multiple) of children workitems (multiple)
3) Automatic triggering work flow action or setting attribute value to other workitem based on changed value of a workitem.
4)Any scripting capability to set values of attributes or triggering action on workitem.
The answers to the above queries are urgent input to one of my important decision.
If any one can provide me any work-around for the above capabilities, that will be of great help.

Thanks in advance.

Sanjib Dutta

The url
https://jazz.net/wiki/bin/view/Main/AttributeValueProviders
I came across in a recent post provides info about the
capabilities of RTC that exactly addresses above requirements.
Now that RTC is supporting workitem customization by scripting
(javascript) which (rather than java) I believe will eventually
flourish and be used by most of the users in future I can see that
following features will be very useful
1) Script driven pre-condition and follow-up
2) Integrate script driven action in state workflow and approval
workflow
3) full API access
Is there any such plan in near future ?