Q: it comes with start ink cartridges (translated from Danish). Does these start ink specifications contains less ink than the normal catridges does
A: Yes. They are about half to a quarter full compared to a normal new cartridge. Pagecounts are all dependant on how much and what you are printing.
Q: It says CN461A - but at some websites it is called CN461A#A80
A: The extra #A80 is likely a regional identifier. Its basically the same printer but built with whatever regulations are necessary for your area such as power consumption.
Q: The ink cartridges have an expire date. What happens after this date
A: The ink will break down and be more likely to clog in your printheads and contacts.
Q: Will the printer require new cartridges before it will print anything
A: Not necessarily but it is advisable to listen to your printers warning messages
Q: Can it damage the printer to use ink after the expire date
A: Damage may not be the best term. It will cause clogs in the ink system which will require additional maintenance. When clogs cannot be cleared then the printer may need to be replaced.
Q: or is it only the quality of the printed that will be affected?
A: Technically yes, but quality will not be noticable in most cases with an expired cartridge. The ink will not be able to apply to the paper and hold a nice solid dot, resulting in a more smeared look on a microsopic level. Your concern should be on hardware maintenance.