re:
I recommend setting up a forwarding rule in Gmail, that forwards all your Gmail mails to your Outlook.com account. That way you won't have to give anyone a new e-mail address, your phone only needs to sync with one account, and any other Windows devices you may have which synch with that same Outlook.com account, will automatically gain access to your forwarded Gmail mails, without you having to setup Gmail sync on any of them. That's the preferred solution.
edit: Oh yeah, and if you want your phone to keep your gmail mails separate from your other mails, then just create a new folder on Outlook.com, and setup a rule to have everything from gmail placed into that folder. You could then even pin each folder separately to your start screen, so you can see at a glance from which account you received an e-mail, despite them all being on Outlook.com.
As for Google docs, I'd recommend migrating those documents over to OneDrive. You first need to Export/Convert them however. Google hasn't put a lot of effort into making that as reliable and simple as possible, as you might lose some formatting here and there. It depends on how complicated your documents are. IMHO that alone is already a good reason not to use Google docs, as it does try to lock you in. Using MS' services just provides a lot more flexibility, as pretty much everyone is rather good at importing or working with Office files, even Google (importing MS Office documents into Google docs works flawlessly, or at least much better than exporting them).