At the moment, when one views a bug one sees all the nice long sets of things one might be able to change at the top, and only after scrolling past them does one get to the text of the bug (and comments thereupon). It strikes me that this order is perhaps inverted; I suspect that far more people are interested in the text of the bug than in all the change options, and thus it would be useful if the text came first and all the things one could (maybe) change came later. As a bonus improvement, bugzilla could delete all the fields that one isn't privledged enough to use, and reduce the space used even more. (Perhaps it already does this and I haven't noticed.)
I have implemented, as you can probably tell, something similar to what you are describing. If you thing it needs further improvement let me know. If a user cannot make a change to a bug, the report is now much smaller also. Leaving only the option of adding a comment, adding themselves to CC list or removing from CC list.