Nothing to do with the falling of Iron Courtain, of course, (You know, somehow going from being a communist country to European Union member
state is rarely devastating for infrastructure) but they are some problems on Danube really. Down to Prahovo in Serbia You will go without trouble. Dams and locks on the river provide for good level of water. Last one thousand miles (Serbia, Bulgaria, Romania) can give You more difficulties. The rates of rain falls are extremely low for some years in the area. Dams keep the water upriver (it is used by agriculture there) and low part of Danube is shallow now. With Your draft
You should be O.K. - the river is declared as fully navigable for vessels of less than 1.9 meters draft
for this year.
But... Apart of tens of WW II wrecks (during th retreat Germans sunk whole the fleet, some 200 ships, there) which are now not covered by water (not a bad thing) some call the lower Danube the biggest traffic jam in Europe
Tens (or may be even hundreds) of vessels were stranded on shoals. The river is well marked, but it does not mean much when most of the traffic there are the barges of much more than real today limit...
So You will have a thousand mile slalom there, but with well manoeuverable boat it can be interesting adventure.
The best thing You can do is to pray for a lot of rain and snowfall along Danube before You go
Oh, regarding pirates... Most You will find in Vienna and Budapest. They tend to cover themselves here as restaurant owners, and will not release You without huge ransom (they call it "bill" for some reason).