Configure Permission & other doubts: help!

[jsoriano]

Hello again, perhaps my last questions were not
so clear... i should to improve my english  ;-)

All i wanna know is:

(1) how can i prevent some users to delete or modify a file?

(2) which is the perfomance of the users & actions folders?

(3) Why can not put a file called 'ejemplo.jsp' in the file folder using the
command line client included in jakarta-slide-10m7 ?

I mean something like...
  [slide]$ put /mydocs/ejemplo  ejemplo.jsp

    i obtain:
       Uploading '/slide/files/ejemplo.jsp'  to  'ejemplo' : failed
       No Found (404)

(4) It's possible to perform 'automatic versioning' to the uploaded files?