1) Copy of activity: Possibility to choose the number of copies ((faster if you have to copy it 10 times)

Not sure it is a very usefull improvement. Do you have some cases when you have ot 'copy' an activity 10 times ?

2) Possibility to have a case in a sub-project to enter the amount (€ / $) and the proposed father adds the sum of the sub project?

It is a improvement proposed on the validated work : have the possibility to set validated work as sum of sub-items.

3) In the report "workload" to choose a project ?

Why not. registered.

4) Possibility to enter some other projects in hours in a day?

I don't understand the request. could you explain ?

5) Possibility of synchronize databases? If I am logged on locally (localhost with WAMP) possibility to sync to the server? A conflict management database is managed by me with specific IHM?

It is an existing request since a long time : very difficult to implement, and not the most expected functionality.

6) The management of invoices?

Planned in V2.0

1) Copy of activity: Possibility to choose the number of copies ((faster if you have to copy it 10 times)

Not sure it is a very usefull improvement. Do you have some cases when you have ot 'copy' an activity 10 times ?

Yes I work on projects with activities related to the versions.
For each version I realize the task 1, 2, 3, 4, and I deliver the milestone 1, 2.
From the start I want to create a template that can be copied 1, 10 or 20 times.

4) Possibility to enter some other projects in hours in a day?

I don't understand the request. could you explain ?

For the same project a resource can work on multiple little activities (analysis, script writing, peer review ...) which is calculated in hours.
I wish I could give the possibility to enter hours in some projects

Last point
On the Gantt view is it possible to hide the black bar (duration of the activity) => Option ?

Thank you and happy new year

Yes I work on projects with activities related to the versions.
For each version I realize the task 1, 2, 3, 4, and I deliver the milestone 1, 2.
From the start I want to create a template that can be copied 1, 10 or 20 times.

As you describe it, it seems you may use template project copy option : a version could be a sub-project, including tasks, milestones and links between these elements. Then you just have to copy the project, including the structure, to copy all the needed tasks.

For the same project a resource can work on multiple little activities (analysis, script writing, peer review ...) which is calculated in hours.
I wish I could give the possibility to enter hours in some projects

It is not possible to mix days and hours input : it would lead to unavoidable rounding errors. But even for small tasks, input in days can be less than 1 : 0.5 for half a day, 0.125 for 1 hour.
My advise : dont' follow up very small tasks : you will spend as much time to follow them than to realize them, and moreover you will never be able to plan them. One good compromise can be to define one gathering task, with some workload for instance planned ad fixed between dates, define your small tasks under this one, just to follow up the status, and input work on the gatering task.

On the Gantt view is it possible to hide the black bar (duration of the activity) => Option ?

I don't understant. Which black bar ? Any print screen to help ?