Few issues!!!

Hi,

I am using RH 8.0.2,previously using RH5 and then RH8

1. Some time in my project file i do not find broken links and Unused file then also it show fatel error and fail to compile.i can see a temp folder in !SSL!,what can be the reason?
2. In few cases, i fix broken links,unused files and compiled CHM file.But again when i open my project i find some new broken links and unused files,Why so?
3. When i import unused files i find index keyword missing.How to fix it?
4. How to avoid problem of broken links and unused file?
5. In one case i compile file with broken links,surprisingly i find everything ok.
6. Is there any link which talk in detail about the use and function of the different files created in RH project?

Br,

Rahul