First, i'm French so Thanks Google for the traduction

I'm new to OTRS and everything works relatively well, but for our business, we would like to improve the registration form for customers.
Indeed, we would require specify additional information in addition to the three default values (firstname, lastname, email):
- company anme
- phone number
- Street
- ZIP code
- city
These fields are mandatory.
Once saved, these values should be recorded in the database associated with the account given of the new customer.
I tried to modify the file: /opt/otrs/Kernel/Output/HTML/Standard/CustomerLogin.dtl (too hard for me now)
but is there a simpler way by changing: /opt/otrs/Kernel/Config.pm
And when I tested the version 3.2.5 recently, it was easy for the admin to associate a company to a client, now in version 3.2.7 it is not possible by default.
I modified the file: /opt/otrs/Kernel/Config.pm to allowed that
and now I have a field: customer_ids in the preferences of the client which list companies that are available but despite this, a customer does not see the tickets of his colleagues from the interface by clicking on "Tickets of my company."
Any idea?
Thank you in advance
Rudwolf