Does a slight emission of air, or the sensation of cold air or bubbles around or from inside the anal opening, and sometimes with every ablution, necessitate repeating the ablution each time?

If what you are experiencing is whisperings (waswasah), then disregard them and pay them no mind. Act according to the principle, which is the absence of passing wind. Therefore, do not repeat your ablution unless you have absolute certainty that it has been invalidated. If passing wind is continuous, to the extent that you do not find sufficient time for purification and prayer, then your ruling is that of a person with chronic discharge (sahib al-sals). Perform ablution after the time for prayer has begun and pray the obligatory prayer and whatever supererogatory prayers you wish until the time for prayer expires. However, if you know that it stops at a specific time, then wait for that time, then perform ablution and pray.