Get inside the mind of Larry Harris!
To speculate on the Italian moves in the sample round one:
Italy can reinforce Venice with enough units to achieve parity with Austria 8 inf & 4 art each. Is it worth attacking with these odds? Not really, let Austria throw its infantry against your machine-guns next round.
So, to divert Austria away from the northern front:
Your transport picks up the Libyan garrison and dumps it into Albania, where it is joined by 4 reluctant local conscripts. Austria has landed itself with war on three fronts, and now bitterly regrets that cretinous and unnecessary attack on Serbia.
The Rome garrison moves up into Tuscany ready to reinforce Venice again next turn.
The Somalian infantry moves into BEA, since it cannot march though Ethiopia.
You place 2 inf and 2 art in Rome.
This would be the standard move given the circumstances.
Alternatives?
Attacking the Austrian fleet is too risky, even if you build a sub or 2 Austria will probably counter-build.
Because of this, its a slow process to move new units up to the Venice front; it may even be worth considering abandoning Venice for this reason. Better to hold a line you can reinforce immediately (Piedmont-Tuscany).
Albania becomes more attractive as you can ship units there from anywhere in Italy bar Venice.
A surprise for the Austrians would be a transport build, allowing you to send 4 units to Albania a turn, or even switch the Albanian army to defend the Piedmont-Tuscany line.
For me the bottom line is that, without rail movement, the critical 2 turns it takes to move new units to Venice means that this tt is best held with minimum force while you build up strong defences in P & T.