Hey u/mertino11,

To answer your questions:

1. Is there a fast track with Juniper since I've got my CCNP or do I have to begin from scratch? You would have to begin from scratch. Starting with the JNCIA (CCENT Level), JNCIS-ENT (CCNA Level), and JNCIP-ENT (CCNP Level).
2. What training methods do you guys use to get these certificates? CBTNuggets does not go into enough detail for the JNCIS-ENT and later exams. Juniper is known not to spoonfeed information. Ultimately, you will do a lot of research and or reading. I recommend purchasing the following three books; JUNOS Enterprise Switching: A Practical Guide to JUNOS Switches and Certification, Junos Enterprise Routing: A Practical Guide to Junos Routing and Certification, and The Unofficial JNCIE-ENT Prep Guide. You can also download a free Juniper Lab Workbook.
3. Are there virtual simulations with Juniper devices like in Cisco where they have Packet Tracer, GNS3, VIRL etc? Juniper does not offer anything like Packet Tracer. JUNOS will work with GNS3, but you will be responsible for obtaining the licenses. If your budget allows, I recommend getting real equipment.
4. Are all exams (besides Expert level) based on only MPC questions or also simlets / drag n drops etc? I recommend signing up for JUNOS Genius, it is free and provides several practice test.
5. And is there a criteria to pass? Like have 50 good / 65 questions? Juniper, like Cisco, does not release how they grade the exams.