We are not aware of a narration that addresses this issue.
<p style="text-align: left;">It is not permissible for the person in the state of janaba to recite the verses of prostration. He may recite the rest of the Quran.</p>
We are not aware of a historical source that clearly indicates this, but offering the prayer behind Abu Bakr does not give legitimacy to his caliphate. Imam (peace be upon him) no doubt was forced to give the allegiance to Abu Bakr. He did so because those people were ready to kill whoever does not pay allegiance. They killed Saâ€™d bin Abadah because he did not agree with them although he left Medina and migrated to Syria and did not resist them. This clearly shows that they were willing to do anything in order to be in power. From this, one can conclude that Imam Ali (peace be upon him) was forced to get along with them. It is not far to consider that such prayers â€“ if it really happened - made them confident that the Imam (peace be upon him) was not acting against them.
There is nothing wrong with visiting Sunni Mosques but the prayer should be according to the sect of the Ahlulbait as believing in their path imposes the believer to so do as they are the smallest amongst the two weighty things that the Prophet (peace be upon him) commend us to refer to.
You did not commit a sin. However, one should pay attention to the fact that the permanent marriage should take place after the end of temporary marriage. When the couple decides to marry permanently and there is still some time left from their temporary marriage, the husband should forgo the remaining time, in order for the permanent marriage to be with a non-Mahram.