1. Is it possible to rename menu such as "ticket" for example? (i have bought customization field plugin)

Not with screen custo.
This is possible with "personalized translations"

2. i would like to put a default value on a reference field but it seems that it does not work. How to proceed ?

Default value is evaluated only on creation.
If you need a "calculated" field, set the field as readlony additionnaly to default value.

3. i would like to display customer on a ticket, retrieved automatically from the concerned project, but it does not work, only a drop down list is available with all customers. How to proceed please ? Same thing that happen in QUOTE screen in reality... Or would it be possible to have a field "customer" displaying the customer from the requester?

Possibly you can manage with default value...
- set field as readonly
- entrer default value as

###EVAL###(new Project($this->idProject))->idClient

Hi,

for point 3 i did what you told me but it does not work. Please see file attached

With files attached

You mlust make some change on the item.
The default value won't be automatically applied to all existing items.

I'm sorry but i do not understand your reply. Which changes ? Which Item?

You showed print for ticket #48.
Try and change it, anything will do (possible just save without any change will do the job, but I'm not sure)

Effectively, i just saved without any change and it works. why do i have to do that unitarily ? is there any solution?

why do i have to do that unitarily ?

Because default value is applied on saving...

is there any solution?

Make a minor change (for instance add a space on description) with multiple update feature