Relationship Question and follow up form question

Greetings,

I have been pouring over this question for a bit and finally decided to ask
here.

I have the following table structu

tblOfficeLocation:
OfficeLocationID - PK(AutoNumber)
OfficeLocation - Text

tblRoomDesignators:
RoomID - PK(AutoNumber)
RoomDesignation - Text

tblOfficeRoomJunction:
OfficeRoomID - PF(AutoNumber)
OfficeLocationID - Number
RoomID - Number

tblUserTable:
UserID - PK(AutoNumber)
OtherFields here
OfficeRoomID - Number

I set up the relationships thus:

An office can have more than 1 room nunmber and each room number may also be
used in other office locations. Enforced RI, and Cascading updates and
deletes for both.
tblOfficeLocation1----mtblOfficeRoomJunctionm----1tblRoomDesignators

Each user will be assigned an office and room number but there may be more
than 1 user at the same location. A user will only ever be assigned to one
location. Enforced RI, Cascade updates only.
tblOfficeRoomJunction1----mtblUserTable

Here is what I want to do:

On the user form(My main form), I want 2 combo boxes. One for the Office
Location and one for the Room Number. Whichever one is used first I want the
other to only list the data associated with the combo 1st chosen.

I would like to be able to update either the OfficeLocation or
RoomDesignation and have that follow through to my user form. I want to be
able to delete a location or room designation via a form without deleting the
user but have the office location and room designation information removed
from the user form.

Now the question:
Is my data structure setup to allow this and, if so, can I get pointers on
how to set up my forms to allow what I want to do?