I don't know about women's rights, but it is a well known fact that (at least in the first period of their history), the Tang did much to stabilise the political and religious power in China, especially concerning the acceptance of Buddhism, which in past dynasties had been seen as a "foreign" religion, and on some occasions even persecuted (not for long, fortunately).
I think that the Tang were surely more liberal than the preceding dynasties.
You used the persecution of Buddhism as an religion as an example of how Tang was more liberal, but almost every dynasty in China except for a specific period of Song [and even that is doubtful] was due more to economic and taxation reason then it is a religious reason.
To say that allowing religious institution to have huge amounts of land without need to pay for taxation, while at the same time attempt to maintain the same expenditure, is stabilizing the political and religious power is simply wrong. In order to maintain all the expenses, government simply levy the taxes that the temples and churches did not pay on smaller land owners. I fail to see how the acceptance of Buddhism is a good argument that Tang was more liberal, and I can assure, majority of Tang emperor have far less interest in Buddhism then previous dynasties.
Also, like most dynasties, the earlier part of any dynastic reign usually see a stabilizing period of peace and prosperity, in fact that can be said throughout most nations in this world. What nation's founding period is plagued with destabilizing political base? The very idea of founding a new nation is one political base eliminating another political base, thus stabilizing by elimination.