who officiated marriages in bibical times?

Families. People did not get married in temples, whether they were pagan or Jewish. In the Roman world diviners of various sorts were consulted, and a priestess of Juno might bless a young bride, but that was all optional.

Depends on what culture you're asking about.

In Biblical times there was no such thing as a Mesader Kiddushin (roughly, one who officiates at Jewish weddings).

I should note that in Judaism "officiating" is not the same as "making the union effective".

i.e. there is no such concept of "By the power invested in me, I shall now pronounce you husband and wife".

The rabbi HAS no such power and cannot make someone husband and wife through a pronouncement.

It depends what you mean. The idea that a marriage must be conducted by an officiant (or anyone in particular) to be valid is relatively modern. For Jewish couples in Biblical times, marriage was basically the signing of a contract-- nobody specific was required to officiate. For Roman couples, a ceremony was performed, but there was no legal officiant.

In the ancient Near East marriages were always arranged. In ancient Israel the marriage covenant (b'rith) was part of the civil law, and there were legal papers that were drawn up which defined the rights of the husband and wife. The wedding ceremony (Chuppah) was all about bringing the bride to the bridegroom's house. The ceremony itself would last 7 days, sometimes longer. There would be great rejoicing and celebration late in the evening on the streets, and also when they arrived for the feast at the bridegroom's house. Once they entered the doors were shut and the wedding ceremony began. The bridegroom would spread the tip of his upper garment over her, then they would proceed to the wedding chamber, then to the feast. There were many friends and relatives, some would travel long distances. The fall was an ideal time for a marriage because it was after the harvest.

A priest or official in the applicable religion, the head of the clan or tribe a betrothal agreement between parents that would be as binding as a marriage

nobody

clergy.