Sort:  

Yes, it was signed by @steemconnect's key: STM8fjX2P5nwGk3q9zYLwsfYnG937CyB9TANP3SnnKcgK9vq46My5
However, since all of steemconnects app accounts have @steemconnect as posting authority, you can't tell which app it was (apart from the very obvious suspicion, though...)

yes. So Dlive could say it was Dtube that made the transaction ;) False flags on the blockchain. I am more concerned about if they had done or followed something else entirely. What then? I am a real person here.

they could, yes :)
Technically, you've given steemconnect any of your posting rights by signing up for the first app. This is to post or comment in your name, delete comments, up/downvote, set beneficiaries, disable curation rewards, limit post rewards , claim rewards, ... You have to trust steemconnect that they don't use that at all on their own.

Steemconnect then gives parts of these rights to 3rd party apps. Strictly speaking you have allowed dtube/dlive to change your followers when signing up, probably together with a couple of other permissions that were listed right before you entered your active key. Whether they use these permissions "responsibly" (what ever this is for them) is of course a different story....

Coin Marketplace

STEEM 0.21
TRX 0.25
JST 0.038
BTC 96989.50
ETH 3378.64
USDT 1.00
SBD 3.23