Sharing a profile between Windows and Linux
From MozillaZine Knowledge Base
Any shared files need to be stored on a volume (drive) that both operating systems can read/write. At one time that meant you had to create a FAT32 volume but most Linux distributions now support read/writing NTFS volumes. The two main approaches to sharing a profile between Windows and Linux seem to be:
The most well known article is called "How To Share Mail Between Windows and Linux" and used to be at http://texturizer.net/thunderbird/share_mail.html . Its still available on the wayback machine at this web page.
Some other articles to read are:
Most articles talk about using FAT32 volumes for shared files because there were poor choices for writing to NTFS partitions at the time. However, most Linux distributions now include a NTFS-3g driver to provide full read/write access to NTFS. Another possibility is to use the Ext2 Installable File System for Windows to access ext3 partitions from Windows. The web page says it supports XP, Windows 7 and 8.1 but doesn't mention Windows 10. However, this thread claims it works fine under Windows 10 if you run it as Admin.
If you are dual booting Windows 8 and Linux it is recommended that you disable the optional Windows 8 Fast Start feature as this can cause data corruption due to Windows 8 using cached data from when it went into hibernation, rather than reading the actual file contents when it is restored. 
IMAP specific Alternative
IMAP accounts are designed to share folders with multiple installations of a email client. They store your mail in remote folders on the mail server, fetching the contents as needed (rather than downloading new mail to the hard disk and reading the local copy afterwards, like POP accounts do).
If you only have IMAP accounts you could use an add-on such as CardBook or gContactSync to automatically sync remote copies of your address books with your local address books. You'd have to create the second profile normally, add your accounts, modify settings and install whatever add-ons you want, but your mail and address books would stay in sync automatically.
This is more work than the first solution (literally share profiles between the two operating system) but will work if you have operating system specific versions of add-ons, and doesn't require you to trust that Thunderbird will use the relative version of a path in the settings.
Information on symlinks: