There are only two ways to describe the transitional form, mammal like reptiles or reptile like mammals. Both can be used depending on the character set. Saying they are still reptiles or mammals is very disingenuous.
Apes like bonobos already walk on two legs sometimes. Early hominins are characterized by greater adaptations to bipedilaty meaning the proportion of time spent on two legs increased. They still spent time on four legs, especially on trees.
Yes it did. Also more brilliant people came into paleontology due to Jurassic Park effect. Assistive sciences like biology, ecology, climatology and geology has been completely revolutionized (genetics, conservation science, plate tectonics, climate change science etc.). Current teams contain 20-30 scientists of diverse disciplines to extract multidimensional data from fossil beds.