Development in a big enterprise environment

I work in a department of 14 business analyst. Our main job responsibilities are from requirement analysis to design the software system. We use UML for analysis and design. After we design the system, the software production take over the design and start coding and then testing and release.
But my concern is what benefits our UML design brings to the production department? Because they don't want to see a 200 page document. So for a long time I was searching for a tool that can help in this environment. Basically I want our output to be the input of production department and their output to be the input of testing department. I also need to manage the security as well because i don't want a programmer to change the class diagram or an analyst to change the test result.

Some tools are too expensive. I found Enterprise Architect by Sparx Systems.
I found this tool helpfull. I tried the demo version. The tool also generate report in HTML and RTF format and help you not to write 200/300 page document. This tool can generate code as well. But the security system not so smart.

I havn't tried Visual Paradism. Rational Rose is too espensive. Is there any tool that can full fill my needs?

Use Case

I have a requirement where user can add an item to the database and if they want, they may modify or delete the item from databse. In this case shall i write one use case for 3 types (add, delete, modify) of operation and put modify/delete options in the "alternative flow" or i need to write 3 use cases for 3 types (add, delete, modify) of operation? i have opinions from people for both cases. But which one would be actual format?

RUP project planning

RUP has 4 phases and the project has to go through that phases. But when i am planning the project i have to give an estimated time to complete the project. RUP says to plan for the next phase in the current phase. in this scenario how can plan for the whole project. If i use UCP method to estimate time, i have to have use cases written. At the initial phase (inception), i don't have use cases written. is there any efficient method to estimate time or i have misunderstood RUP?