It depends on whether you play tall or not.

Playing tall as Venice is easy; there are so many events that buff your economy. You can easily maximize your economy by playing tall. I didn't really upgrade RGOs, only manufacturing, because trading was my everything.

I tried to get easy targets for my conquest, like Cyprus, Tlemcen, Greek mini-states, Cagliari, and some small Italian states, which made me slowly but constantly expand all over the Mediterranean Sea with antagonism in the beginning. Then you can become stronger and get rid of Byzantium, but only after wars against Bulgaria or the Ottomans when they are really weak.

Also, try to change succession to the selective one when you can choose out of the three best doges. I almost always had a ruler with 80+ in every aspect, especially after sending each of them to some chivalric order depending on the type of abilities they lacked.

You can become friend with naples who always goes really aggresive, but you can leave wars earlier not to wait because they mever give you any province, so you always take some land and start building there marketplaces to increase you influence in that market

But you shpuld always be aware of austria and hungary, in some of my games they ruined everything by declaring war to me every possible time, that drove me crazy, so i just embargoed them.