Q1: Yes, given that no "beating higher tiers" is involved.
Q2: Yes. "Consistently" is not necessary. A 50 - 500 record still shows 50 wins which should have "some" relevance.
#3: I've seen this, too. Those have taken their promotional average and worked from there to further advancement. But IMHO, it's not wise to accelerate the tier movement while the levels remain low.