Which way do you want to sync? Thunderbird to mobile device, mobile to Thunderbird or both.
Out of your list of spreadsheets/calendar/contacts/tasks/office, AFAIK Thunderbird does not have a spreadsheets, calendar, tasks or office.
I sync Thunderbird contacts and Orage (Xfce's calendar) to a Nokia ExpressMusic phone by manually exporting the address book and the calendar then use self-written bash and awk scripts to re-format them and load them to the phone using gnokii. It's not slick and a few contacts get lost during the loading
More in my LQ blog here
The latest version of Orage supports programmatically exporting the calendar to save one manual step but Thunderbird does not support that and its address book format is so labyrinthine and undocumented that it is improbable that any code can be written to take the address book directly from the file system. The Thunderbird devs have been intending to implement a cleaner address book data format for a while but that now seems unlikely given the development status of Thunderbird. Perhaps the SeaMonkey devs will do it with their fork. Would be nice.