Please, check which ranking quests are still available in your case => you need about 10000 ranking XP to beat Serrick on the ranking list. And max is 25000.
Stolen goods 1500
Talking Tibar 2500
Lost relic 2500
Ball in well 500
Book for Barnabus 2500
Book for witch 2500
Man turning into crystal/cure for... 1500+1500
Kill an assassin 1500
kill Fire Elemental 500
Zandalor wants an artifact 500
Missing monks 2500
Strange teleportations 5000
The crypt will only be open, after witch Kiya challenged you, so you need a bit more than 10000 ranking XP.
Library => Didn't Cytha flag the area for you? It's on Ruins Island. After you enter there and question the librarians, you need to find out the cause of the smelling lava in order to proceed.
