Inheritance Questions

I would like to ask you to examine the following facts and consider 
their implications.
The following program compiles correctly and produces the expected output.
=========================================================
class TEST

creation  program

feature

   program
   is
      do
         create staff.make;
         staff.add_last(create {EMPLOYEE}.with_salary(25000));
         staff.add_last(create {EMPLOYEE}.with_salary(22500));
         staff.add_last(create {EMPLOYEE}.with_salary(20000));
         staff.do_all(agent show_employee(?));

         std_output.put_real_format(staff.salary_bill, 2);
         std_output.put_new_line;
      end

   staff : STAFF_LIST;

   show_employee (e : EMPLOYEE)
      is
      do
         std_output.put_integer(e.staff_number);
         std_output.put_new_line;
      end
end


class    EMPLOYEE

creation  {TEST}  with_salary

feature {TEST}

   with_salary (initial_salary : like salary)
   is
      do
         staff_number_allocator.increment;
         staff_number := staff_number_allocator.value
         salary := initial_salary;
      end

   staff_number : INTEGER;

feature  {TEST, STAFF_LIST}

   salary : REAL;

feature  {NONE}

   staff_number_allocator : COUNTER  is  once  create Result;  end

end


class    STAFF_LIST
inherit  LINKED_LIST[EMPLOYEE]

creation  make

feature  {TEST}
   
   salary_bill : REAL
   is
      local  employees : ITERATOR[EMPLOYEE];
      do
         from  employees := get_new_iterator;
         until employees.is_off
         loop
            Result := Result + employees.item.salary;
            employees.next;
         end
      end

end

---------------------------------------------------------------------------------------------

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67500.00

==============================================================
If the class STAFF_LIST attempts to "insert" rather than "inherit" the 
LINKED_LIST, the program fails to compile with the following message:

compile test -o test
****** Fatal Error: Cannot pass `other' which is of type STAFF_LIST
into formal type COLLECTION[EMPLOYEE].
Line 190 column 20 in LINKED_LIST (/opt/SmartEiffel/lib/storage/collection/linked_list.e):
         from_collection(other)
                         ^     
Line 284 column 26 in LINKED_LIST (/opt/SmartEiffel/lib/storage/collection/linked_list.e):
   from_collection (model: COLLECTION[like item]) is
                           ^                        
------
File "test.make" not found. Error(s) during `compile_to_c'.

Compilation exited abnormally with code 1 at Thu Apr 14 09:13:29

==============================================================

Now if the following export clause is applied to the inherited 
LINKED_LIST then the compiler produces 69 messages. This
output is elided as all the messages are similar and originate in the 
library classes.

export {COLLECTION, GENERAL, LINKED_LIST, NONE} all;

                    {LINKED_LIST, TEST}  make, add_last, do_all
            end

----------------------------------------------------------------------------------------------

compile test -o test
****** Warning: The client list computed from the "export" clauses
is narrower than the one from the conforming parent(s). This can
lead to catcalls! The final export list is {COLLECTION, GENERAL,
LINKED_LIST, NONE} .
Line 96 column 9 in COLLECTION (/opt/SmartEiffel/lib/storage/collection.e):
feature {ANY} -- Writing:
        ^                
Line 107 column 2 in COLLECTION (/opt/SmartEiffel/lib/storage/collection.e):
   swap (i1, i2: INTEGER) is
   ^                        
Line 3 column 21 in STAFF_LIST (/home/.../staff_list.e):
            export  {COLLECTION, GENERAL, LINKED_LIST, NONE}  all;
                    ^                                             
------
...
...
****** Warning: The client list computed from the "export" clauses
is narrower than the one from the conforming parent(s). This can
lead to catcalls! The final export list is {COLLECTION, GENERAL,
LINKED_LIST, NONE} .
Line 122 column 9 in GENERAL (/opt/SmartEiffel/lib/kernel/general.e):
feature {ANY} -- Basic operations:
        ^                         
Line 130 column 2 in GENERAL (/opt/SmartEiffel/lib/kernel/general.e):
   is_default: BOOLEAN is
   ^                     
Line 3 column 21 in STAFF_LIST (/home/.../staff_list.e):
            export  {COLLECTION, GENERAL, LINKED_LIST, NONE}  all;
                    ^                                             
------
****** 69 warnings.

Compilation finished at Thu Apr 14 09:02:17

==============================================================
Quite clearly there are many other ways in which the functionality of 
the above program code could be achieved.  Many of  these would avoid 
the difficulties I am considering as they seem to indicate that further 
thinking is required.
Working program
    demonstrates that the basic functionality is valid.
Version with "insert"
    From a SmartEiffel programmers point of view, should the version 
using "insert" also be expected to be valid?  The errors would then be 
seen as a library implementation problem, rather than a problem with 
inheritance?
Version with the export clause
    The export clause is clearly intended to restrict access to the 
features of the STAFF_LIST and would appear to be a perfectly desirable 
method of re-using existing classes.  Imagine using this technique in a 
substantial program in which it occurs frequently.  Any warnings about 
the actual programmer's code would be swamped in these messages!

So I would like to pose the following questions particularly to the 
theorists.
          Does the above demonstrate a missing Eiffel inheritance 
facility akin to "inherit" and "insert"?
          As the above seeks to impose restrictions on the inheritance, 
would the use of a further facility
          such as "restrict" improve the ability of a compiler to work.
Regards
Frank Salter