To host website on Qortal blockchain should I be more than Lvl 0 ? Or it doesn't matter ?
Level does not matter, you'll only require some QORT to register your name and you'll be all set.
Good, thank you for an answer.
And what about buy orders on trade portal ?
People still can't place order to buy at price they want. Why ?
So many new versions of the Core and UI have been released lately, but there are no positive changes on this issue.