Dealing with fullwidth submenu styling and permalinks

Hey!
I’m trying to change a few settings for one page (see private link).

1. If I click on a submenu item :
– the selected item stays gray #919191, I’d like it to stay the same color than when you mouse over (#666666).
– the main item above (in the main menu) is not green anymore. I’d like it to stay green as long as I am in this area. Is this possible ?

2. Same for the “level” below. If you are in “Quel type de cancer” (which then should #666666), and then if you select “Sein”, I’d like “Quel type de cancer” so stay #666666 and “Patients” to stay green.

3. Is there a way to have permalinks that reflect that hierarchy ? I’m kind of lost here…
Ideally and as an example I’d rather have “site/patients/quel-type-de-cancer/sein” than “site/sein”
or “site/patients/comment-ca-marche” rather than “site/comment-ca-marche”.
But is this possible as those “inner pages” are not included in the main menu ? Is there a solution ?

Thanks for your help!
Best regards,
Marie

PS : No answer to my yesterday post… well the site is not messed up anymore so I feel relieved and I can keep working, but the header remains “unfixed” in chrome and firefox. So better for you to look at my link in Safari. + I would really appreciate some help or explanations regarding this matter (of the unfixed header in chrome & firefox). Thanks :)