OK, to help TheriOn here, as I'm French too, and hit *sometimes* the same issue.
I have 2 accounts :
a) a personal live.com one
b) a professional one, Office365 for SME
There are many issues with the Office Mobile suite, on PC and mobile according to me :
1) no real multi-account management
2) licence issues.
By 1), I mean that even if I add my office365 account (by clicking on my name on the upper right corner in any Office Mobile app), then I can't *switch* from an account to the other. It's the first registered account which is recognized. This leads to many stupid situations :
- In OneNote, I can open my personal notepad (on mobile and PC), but I can't open my pro one on the 535 (requires 535) when it's OK on my pro iPhone or my PC running W10 (with exactly the same accounts)
- In Word or Excel, I can't switch from one account to the other (PC or mobile)
My educated guess is: the 2nd account management is still alpha in the mobile build. In 10149, we couldn't even add another account in Office suite. Now it is possible (Onedrive is a perfect example), but clearly, it's not advanced enough to be able to switch amongst accounts (and if this shouldn't be possible, then why offer to add multiple accounts in these office apps?)
By 2), I mean that /sometimes/ it asks to activate an office365 licence, which I don't own for my personal account (for editing or creating a document). Insisting works most of the time to get through.
So I don't understand what we should be able to do, or not, with a "free account". I use all office apps on my pro iPhone 5S, and also on my PC with W10 technical preview, and, as I said, W10M on a 535. This gives me 3 comparison points, and only show the inconsistency between apps.
I would say that W10M and the "mobile" part of these stock apps will be polished/improved after the 29th of July (example: SMS receipt tick mark, etc., in other terms, all these "specific" mobile-only features not needed on PC. Other example: the return of the ability to set quiet hours according to meetings in given calendars, as on WP8.1, that Cortana can't manage on W10/W10M at this stage, I guess because quiet hours is not a priority for the PC release).
Now back to the topic, let's trust the OP when he says he has difficulties to "activate" or use even basic features of Office Mobile, without turning this into an OS/platform competition, or a lack of understanding of what Office365 is.
Now to answer to N_Larue, that screenshot is a simple ad for office 365, which sells all the unlocked features a subscription brings (install Office on PC/Mac, get 1 TB on onecloud, etc., with a link to MSFT website to buy such a subscription).
Bottom line: let's way A) the official release of W10 and Office Touch, B) the same for W10M, before jumping to conclusions when comparing to iOS or Android. In the meanwhile, I've reported all these points (inconsistencies, etc.) via the feedback app on both PC and mobile builds.