How to change default saving pattern

Hello, I use Calibre with eBooks, but also loads of aeronautical books, programmation guides, cook books, comics, magazines and travel guides. I found it perfect with the customizable column (fields). Furthermore, my entire library is on a NAS, which makes it available from any device...

The main problem with calibre is that it saves through a pattern like Author/Title, which is really not relevant for the kind of digital books I have...

So I have 2 questions :

1) How to change the default pattern calibre uses to save books ?
I'd like to us my own fields to rename folders and books, and as a test to change the pattern wether it's one kind of book or another...
To be more accurate, I'd like to test my own field "Catégorie" (yes it's in french), and put the book in a folder in accordance :

Test [Catégorie] /
* If «*Book*» —> / [Auteur] / [Série] / [Title] ([Auteur])
* If «*Guide*» —> / [Sous-Catégorie] / [Série] / [Titre]
* If «*BD*» —> / [Série] / ’T’ [N°] ‘-‘ [Titre]
* If «*Mag*» ou «*Journal*» —> / [Série] / [Série] [N°] ‘-‘ [Du] ‘au’ [Au]
* If «*Beau Livre*» —> / [Série] / [Titre]

My personal fields are Catégorie (Category), Sous-Catégorie (Sub-category), N° (Number), Du (From), Au (To)...

2) How to use the server from the NAS (synology) directly ? I tried several packages like BicBucStriim or COPS, but it doesn't work at all...

Thanks for your help.