Must the prayers that were performed with tayammum and wudu be repeated if there was a state of major ritual impurity (janabah) due to insufficient water for ghusl, and is the janabah lifted by the very first tayammum?

The correct approach is to perform tayammum for prayers while in a state of major ritual impurity (janabah) when water is unavailable. You are not required to repeat the prayers you performed with tayammum due to the absence of water. However, the prayers you performed with wudu while in a state of janabah are invalid, because the obligation for a person in janabah who cannot find water is tayammum, not wudu. Allah the Almighty said: "and you find no water, then perform tayammum with clean earth." So, wudu does not substitute for ghusl or tayammum, and tayammum does not remove janabah.