Resource Types

In projector we can define many types of elements, except resource types, is that true?

Yes
There is no type for activities because there is not status on resource, so no workflow to define.

I mean that instead of assigning each activity type to each single resource, assigning the activity to a group of resorce from which the projeqtor will select the most available one.

This is IA, and ProjeQtOr is not an IA.
For instance, there is no easy definition of "the most available one".
Moreover, the resolution of such problems are why quantum computer are desgined : seems easy problem to solve, but with so many possibilities (when addinf several tasks) that is cannot be solved by standard algorythms.

Hi,
It's not that simple.
I mean, your first purpose is "assigning the activity to a group of resorce from which the projeqtor will select the most available one."
The real problem is which is the "most available" ?
Example :
A is booked : XXXXX XXXXX _____ XXXXX XXXXX
B is booked : XXXXX XXXXX XX___ ______ ______
Is I have an activity to book on third week for 5 days, A seems the "most available" on the week, but will have no most availability after, and Booking B will have worst planning for this task, but may lead to global better planning as B is free after, and this will allow to book A for another task on week 3.
Moreover, it is still more compicated is A and/or B take part to a pool : then they may be possibly booked through the pool, or it may be another resource of the pool (cannot get information at this point).

So yes, your idea is good, but really very difficult to implement.

Assign a type of resource to a type of activity, and another same type of resource to a same type of another activity, and so on. Then calculate activity planning to see the result. Change continuosly the resource assignments among the same type of activities, and see if it fits, or not. So, many manual experimental iterations.
Anyway, i think that's nature of projeqtor i suppose.

And it is what Pools are designed for.