A lengthy consideration on Ryzom's status as a PVPer - English

see how many pvp kills they had. Another thing we could do is show a record of someone's pvp kills. Who they had defeated and when.

It looks like that: https://zkillboard.com/ (another game though, not Ryzom).

This can be done via API. The old Ryzom Armory could track locations and equipment of characters, perhaps tracking PvP kills could also be implemented.

who wants to show how many kill he did today, yesterday, the past weeks?

Strange question. Many PvP players absolutely love all sorts of ladders, top killers lists and things like that. That makes competition more fun and interesting. Bragging rights, statistics, records for memorable kills, and it's easy to tell who is indeed a skilled PvP player judging by number of kills.