4) I lied it only does it 3 times
Toll! Though it's only for non-oversea province. It's Trade Efficiency * Base Tax.
Government buildings aren't affected by being oversea, but generally avoided unless you're colonizing as non-western tech.
Army and Naval are avoided except for docks, which has the best return rate, oversea or not. 50 * 8 / (trade value) for the break even year (disregard if it produces gold)
Constables are always good, but consult the ledger building page and sort by tax income. 50 * 4 / (tax value) for the break even year. Avoid the rests unless it's a CoT, which you should go to at least lvl 4, maybe 5.
Marketplace is the 2nd most cost-efficient building by itself, and great when you have a big colonial empire. It also leads to trade 5 and 6 for the national modifiers, which is always a plus unless you're playing with 5.2 beta. Though it's still better to focus on non-oversea rich provinces over colonies.