All Minters sign blocks that is proof they are online. There is no way to tell who is signing vs who is making a block until the block and TX is accepted by all nodes. From what I saw there are Zero Confirmations too so it is fully unhackable. I saw on discord that they consider the 1 block a confirmation. Most coins must lock coins for multiple confirmations so this would mean Zero Confirms the way those Crypto operate. Seeing that Qortal is different it may not even adhere to Normal standards and I hope to learn more.

So if you send a TX it is going to be written to the next block. Unless it is a Free Chat TX that never gets Confirmed and drops after 24 Hours. Great way to implement something and not bloat the Chain!