One thing that is a big motivation for me is collecting nymphs and marks so I am very much in favour of keeping those mechanics and a way to import your collection. At least for marks and those codes used on nymphs.
Have implemented a proof of concept this morning (
ie it's on my local version, but have not deployed). Process will be typing '/importaccount' in chat, where you will then have a form to enter your username/password (I suggest changing your password on etg when you do this), server will then import marks & nymphs as shiny nymphs (openEtG has nymph packs to not restrict their pvp availability, but cannot be polished, 'shiny' serves to give a late game which doesn't impose a barrier to quickly being able to have a full pvp playset). PS eventually planning to make Marks behave the same as pillars, only with alternative art