Does the suspected passing of wind during prayer invalidate ablution, and is it valid to doubt the position of the Tashahhud and then complete it and perform the prostration of forgetfulness?

If you doubt whether what exited you was a wind or not, then your ablution and prayer are valid, due to the Prophet's (peace and blessings be upon him) saying: "He should not leave (the prayer) until he hears a sound or perceives a smell."

The Tashahhud is sufficient with any wording narrated from the Prophet (peace and blessings of Allah be upon him). The one adopted by most scholars is the Tashahhud of Abdullah ibn Mas'ud. If you predominantly believe that you have performed what is sufficient for the Tashahhud, then your prayer is valid, and you are not required to perform the prostration of forgetfulness (sujud al-sahw).