The wildfly plugin in Netbeans supports incremental deployment : using exploded structure and copying only modified/recompiled files.
This depends on your project configuration. Have you checked the "Deploy on Save" check-box in Project Properties -> Run ?
It might depends on the size of the project when reloading it but I agree it shouldn't take this long.
This is almost instantaneous on my machine but I use only sample code like quickstarts to test. Could you open a bug entry with your logs and runtime informations on Netbeans bugzilla ?
Finally now it got better. Redeploy takes only 15 - 19 seconds. Sometimes no redeployment is needed. The problem was we had a lot of mess in our project and so a lot of things couldnt work well together. Thank you very much for your answer.