I also believe that the starting moves will either make or break you, so here's my take.

wait for venice to contact you (which is actually pretty early on, first or second turn kinda early) and sell all your goodies (trade rights, map info, etc) but NOT an alliance. You want to remain reliable. Rinse and repeat with Milan, only use your own diplomat to contact them.

Wait for the papal diplomat to ask for trade rights, and then spring the big question (will you ally with me?). Gift them military access, map info, and enough florins to take you to the top of the papal list. If you attack any catholic faction before allying with the papal states, it's near impossible to do.

Once you have the pope in your pocket and a diplomat camped outside of rome for the occasional florin gift, use all that cash you've accumulated from selling trade rights and maps to buy some mercs with your faction leader, and then siege Venice. They're going to attack you anyways, so don't feel bad about it.

After you whipe out venice and any relieving forces in a bridge battle, set your sights on Milan and Genoa. Milan will attack you anyways as well, and you want to disable these italian superpowers before they can turn their piles of florins into piles of crossbowmen and militia spearmen.

Once you've secured Venice and Milan is out of the game, set your sights on Sicily. Here's another power that is hell bent on attacking you, and their fortress in Palermo hits citadel around 1115. You wouldn't want a citadel being wasted on norman knights when it COULD be making Zweihanders, would you?

Once Sicily is removed, probably with the help of mercs, you have a central med. base that produces some of your best infantry. You're in a prime position to follow any crusades that are called, and you can have at the southern bit of france in a few turns of sailing.

I prefer to keep some powers in the game that blossom, so that I have a bit of competition when I get my good units (because that's when the fun really starts anyways), so I don't bottleneck Denmark by taking hamburg (I bring the troops down to help with Milan, actually), and I leave all the rebel provinces becides Prague to the poles (who need it anyways). In my opinion, it's better to set up camp in italy and a bit of southern germany than to freeze one's arse off in the cold and poor northern germany.


Now remember, your starting units suck compared to merc spearmen and merc crossbows. Try to snatch these up whenever possible, and don't be afraid to make mailed knights up the wazoo for flanking those Italian spear militias.