Why is Indira given so much of liberty? He would work against lord Krishna during Govardhana instance, He involves himself with Ahalya! Where in Bali was someone with more Dharma than Indira.. why would lord vishnu want to protect Indira?
Srimate Raamanujaye Namaha,
Swamy, Indra is a post.. so it is not the same soul who is involved in all the instances you had indicated.
Secondly, In general Indra is a devotee of the Lord, but in exceptional circumstances such events happen, which the Lord forgives mercifully..
Because of this nature of the Lord only , we are also getting the mercy of the Lord, otherwise imagine our situation.
Srimathe Rangaramanuja Mahadesikaya Namaha
Srimathe Sri Varaha Mahadesikaya Namaha
Sri Velukkudi Krishnan Swamy Thiruvadigaley Sharanam
Indran had ShApam after pathivrathA Ahalya apachAram.
Also it is easy for us to get ego. When we see rich people , they think they are better and elevated.
Everytime Vishnu wants to kill Ego he will teach a lesson. Indra is also a Bhaktha. So the leniency .
What it teaches?
Even if it is Indran
தவறு செய்வது இயல்பு
மனித இயல்பு மட்டும் அல்ல