Hi Rodrigo,
After seeing all your screen shots I understand that you are creating an EC within standard Opportunity as a Tab. Now my question is where are the fields( I mean which BO) you are showing in these ALPs( Advanced List Pane).
Generally we create an EC for showing the fields added in standard BO or to show the fields of a custom BO which is linked to Standard BO with some key.
In the way I see you are using the custom BO Bo_Opp_SpecialRelease and trying to link you data model root to standard BO which is confusing.
Because you cannot have add an association within XBO's. It is only possible to create an association to standard/custom BO's only within the Custom BO's but not in XBO.
Now coming to the QC Like behavior on the button which you are trying to achieve does not require all the steps you are doing provided you don't need to pass any data from here.
Just setting the Semantic to QC and binding the ID should Do. Nothing else is actually required.
But QC is used when you are embedding a complete BO within a ALP, like you have contact tab within account( as an example ).
Binding along with firing Outport and Inport are required when you need to pass some data from here the parent component which is normally the case when you have the button within TI.
Talking about the same example if you see the button new in contacts tab in Account TI it has a outport and inport mentioned because any contact created from Account should belong to same account and hence Account ID should be passed to link it to contact.
What Jens document How to create a List Modification Form? has can be used in the case of creating a child node within a BO is what my understanding.
Most of the standard ALPs use this as Jens mentioned. But all the OWL's would have the button New which is a QC behavior if you had observed.
So my understanding is when you need to create a whole new BO which is linked to current BO it should be QC like behavior and when it is just a node with [0,n] relation List Modification Form makes sense.
Please feel to correct me if I am wrong.
Regards
Vinod