It isn't unusual for votes to go against their party faction, though the parties do generally have rules that allow the party to demand they follow the party line in certain situations, though they can't legally enforce that. The worst they can do is exclude said person. There have been a number of situations where there have been important cases where they've tried to enforce a specific vote and members have left the party in question in order to vote as they pleased, which makes the parties careful about when they use those mechanisms.
But the ability for smaller parties to get in also mean that each of the parties are far more homogenous than the US parties, for example, so it's natural for them to toe the party line to a reasonable extent for important votes. In US terms, most of the parties in the current Norwegian parliament would've been members of the Democratic Party, but in Norway that span is considered so wide that it would be unthinkable for any of the current parties to merge.
In terms of barriers, there's a 4% limit below which you need to get in on direct votes, but no other limits (other than being able to fill a list, so you need at most a couple of dozen people willing to put their names on each regional list for parliamentary elections - a low enough number that even parties with a few hundred members have no problems fielding lists in parliamentary electins). The way the Norwegian system works is that most seats are tied to a region, so there's, say (I haven't looked up the actual number recently), 18 seats for Oslo. Each party provides an ordered list. So for the first 2 people on a party list to get in on direct votes, they need the total number of votes for Oslo / number of seats * 2, or more.
All the parties that get more than 4% nationwide then shares in a pot of additional seats that are used to even out their share to best match the actual nationwide percentages. Which regional party list is awarded the seat depends on who got closest to getting in, but the party is determined based on proportion of the vote.
The combination of this is that small parties have a chance of getting in - it takes 15.000-20.000 or so votes per region to win a seat - and larger parties proportions are further evened out so there's no tactical advantages in fighting harder for "close" seats. At the same time a regional link is maintained, which tends to be one of the thing people like to use as an argument for single seat constituencies.
In terms of compromises, I think Belgium has a big problem because it is too disparate. Belgium has two alternatives: Devolution of power (or splitting the country up), or compromises that nobody will be happy with but that are still better for either side than if the other side were to shove things down their throat. When these types of compromises are bad it is usually a sign that both sides to some extent would prefer to shove decisions down the other sides throat, or they could've agreed to devolve more power to the regions...
Norway does have enough conflict too where neither side are happy, but that's the nature of a system that represents everyone reasonably well.
But the ability for smaller parties to get in also mean that each of the parties are far more homogenous than the US parties, for example, so it's natural for them to toe the party line to a reasonable extent for important votes. In US terms, most of the parties in the current Norwegian parliament would've been members of the Democratic Party, but in Norway that span is considered so wide that it would be unthinkable for any of the current parties to merge.
In terms of barriers, there's a 4% limit below which you need to get in on direct votes, but no other limits (other than being able to fill a list, so you need at most a couple of dozen people willing to put their names on each regional list for parliamentary elections - a low enough number that even parties with a few hundred members have no problems fielding lists in parliamentary electins). The way the Norwegian system works is that most seats are tied to a region, so there's, say (I haven't looked up the actual number recently), 18 seats for Oslo. Each party provides an ordered list. So for the first 2 people on a party list to get in on direct votes, they need the total number of votes for Oslo / number of seats * 2, or more.
All the parties that get more than 4% nationwide then shares in a pot of additional seats that are used to even out their share to best match the actual nationwide percentages. Which regional party list is awarded the seat depends on who got closest to getting in, but the party is determined based on proportion of the vote.
The combination of this is that small parties have a chance of getting in - it takes 15.000-20.000 or so votes per region to win a seat - and larger parties proportions are further evened out so there's no tactical advantages in fighting harder for "close" seats. At the same time a regional link is maintained, which tends to be one of the thing people like to use as an argument for single seat constituencies.
In terms of compromises, I think Belgium has a big problem because it is too disparate. Belgium has two alternatives: Devolution of power (or splitting the country up), or compromises that nobody will be happy with but that are still better for either side than if the other side were to shove things down their throat. When these types of compromises are bad it is usually a sign that both sides to some extent would prefer to shove decisions down the other sides throat, or they could've agreed to devolve more power to the regions...
Norway does have enough conflict too where neither side are happy, but that's the nature of a system that represents everyone reasonably well.