So it turns out I was look way to deep for this simple task.

This is available straight in the accounting board (not sure of the translation; "tableau de bord" in french). You have to create first a bank account for your society and a journal linked to it. The journal would than be available on your accounting board.
There will be a button (and later a grey link after the first import) 'import statement' (or something similar, "importation d'un relevé" in french). From there, it's pretty straight foward. Note that your bank account needs to have the full bank id, not just the folio (815-12345-12345678-EOP, for ex).
Also, it seems that the original bank import module interfere with the bank_account_statement_import module and the OCA bank_account_statement_import_ofx module. The only way to access ofx import is the one mentionned above, but their exist two other ways of importing bank statement, which you want to avoid if you're looking to import ofx.

1. On the accounting board, in your bank journal, their is a 'more' button which will span a menu were you find a import statement option. This will bring you to the original importation tool which only offers csv importation. 

2. In the Accounting module, under 'Settings', you will find 'Accounting'. Expand it and there will be 'bank account' (I'm not sure of the term, I'm translating from my french version). Click on it and click on the bank account for which you want to import a statement. Then, under the 'Actions' button, you'll find the option 'Account statements'. Click on it and it will bring you to a page were you see all statements linked to this bank account. You will also have the options of creating or importing new statement. Importing will bring you to the original form where you can only import csv.