Can I use any type of java framework or library like ex: JavaFx, JDBC, Smile or another by using kotlin without using a singleline of java code?
Regarding Korge, it uses Kotlin only libraries mainly from Korlibs (https://korlibs.soywiz.com/)
As long as you are targeting the JVM you can use any java library you want. If you plan on going multiplatform it’s a bit more complicated. You can use java libs for the JVM side and then use different libs for native/js.