Yes IPFS computes a hash, even though it's a bit involved so the hash won't be the same as Blossom's or what sha256sum tells you.
Lack of a DHT is a big one. IPFS's DHT is what they claim makes it scale ("interplanetary" lol) but it's poorly designed and doesn't actually scale well. You'll find lots of timeouts and "content not found" even though the content it out there somewhere.