How much item level we need for the new content?

[Vahlnir]

Not everyone can/is doing endgame. You can get i390 Yama gear in Rhalgr's Reach.

Most anything one does after reaching max level is considered end game content though, so....

You don't have to do endgame to get tome gear. Tome gear is meant to be endgame gear for those who don't raid or do other high-end content.

Pretty much.

Also, there is Eureka which can be considered side content with a touch of casual, midcore and hardcore depending on what one's goals are. If one suffers through Eureka you can get 390 gear on the left side excluding the belt and a 405 weapon. Orbonne also throws 390 gear at people though it's 1 piece per week.