Hey Arie,
No, TurboActivate only returns the days remaining. You can, however, get the "implied" start date by hardcoding the "known" trial length in your app, and using the "known" length of the trial and the trial days remaining to get the start date.
Also, verified trials *do* support extra_data, you just can't *get* that data from within your app (you can *set* it within your app): https://wyday.com/limelm/help/extra-data/