I'd love that "Hive logo + Reviewed" full screen in higher resolution :-)
videos are not uploaded to blockchain, such services like dtube or 3speak are using their own storage such as ipfs, etc. while the Hive post itself has only link to it. Same goes for images that are stored on third party servers.
When it comes to account creation, accounts on Hive are not free (even if you can get them for free sometimes), there's always a cost of account creation, currently it's 3 HIVE. Generally you also don't get free HIVE when you sign-up, some account providers might give you or delegate some amount in HP but by default new account is empty. It has however something called "adjustment" so even empty account can transact on Hive as if it had 3HP equivalent in Resource Credits.
tl;dr Every account takes its name forever and can use Hive resources forever (a little but still)
RE: I made a video introducing people to HIVE, let me know what you think