Short answer 1) Yes—Bitcoin has orphaned/rolled back blocks…

Short answer
1) Yes—Bitcoin has orphaned/rolled back blocks because validating nodes (and the economic majority running them) rejected them.
- 2010-08-15 “value overflow” bug: An invalid block created 184B BTC. Patched nodes rejected it; the chain reorged to exclude that block and its descendants.
- 2013-03-11 0.8 vs 0.7 chain split: Due to a consensus bug, two chains formed; the one with more work (0.8) was abandoned after coordination, and its blocks were orphaned in favor of the 0.7-valid chain. That’s a clear case where the eventual canonical chain was not the then-longest.
- 2015-07 BIP66 soft-fork: Some miners produced blocks with non-DER-encoded signatures. Fully validating nodes rejected them; several-block reorgs orphaned those invalid blocks. There have also been occasional single invalid blocks mined and immediately rejected over the years.