Also if true, what kind of situation did this create for the kingdom? Why was there never a coup attempt? What did her subjects/other countries think of her? Also why did she want to submit to the pope when it apparently (according to the movie) went against her very nature?
Thank you in advance for any responses and if someone could enlighten me on her reign in general, if it was significant in any way.
As far as I know, there were no evidence of lesbian relationships of Queen Kristina. There's no evidence that she ever slept with a man either.
However, surviving letters speak of great fondness and perhaps also love between her and the Swedish count and military officer Magnus Gabriel De la Gardie during her youth, and her letters to Italian cardinal Decio Azzolino were also quite romantic, and being clear that she loved him. He was also the one who inherited her estate when she died.
However, it is clear that she was deeply religious and that she resented the many bastards that her cousing and intended husband the latter King Karl X Gustav sired.
The unwillingness of Kristina to marry and sire a legal heir did create a problematic situation for the Kingdom of Sweden and the pressure on her to marry Karl Gustav was immense - however, as a reigning monarch and with her father dead at the field of Lützen 1632, there was no-one who outranked her and could force her to marry anyone. However, as a monarch it was also her duty to ensure the succession. In the end, she probably felt that she did not have the options Elizabeth of England had, to continue to rule and let James of Scotland inherit - while Karl Gustav had the right to inherit, his power base was very small, and civil war could have been the result - especially as the Polish Vasas were still around in the form of her second cousin John Casimir Vasa.
In the end, she had studied catolicism and believd it to be true, wanted to convert but knew she could not as the Queen of one of the primary protestant powers of the world. She also knew she had to secure the succession of Sweden as one of her primary duties. Unwilling to marry Karl Gustav, she instead abdicated the throne in his favour in 1654, left Sweden and converted to catholicism.
As for her reign, it was marked by an almost unchecked expansion of noble power, as she pawned of royal land to her many favourites or as security for the many loans she took to maintain the dazzling court and cultural life she brought to the otherwise rather medieval and drab Stockholm.
Some say that she laid the foundation of much of the art, museums and culture we enjoy today, others that she bankrupted the state, upset the ancinet peasant-monarchy alliance that kept the nobility in check and neglected the source of Sweden's prestige, status and power - the army.