Does Viber even support Java? I keep hearing that it crashes and crashed on Nokia phones.
Yes, Viber supports Java phones, more exactly the Nokia ones. You can install it on Nokia phones using the Jar/Jad package. However, you should check your Nokia Ovi Store to download it. In case you experience issues with it, I recommend you contact the developers using the following URL: https://support.viber.com/customer/portal/emails/new