K2 blackpearl using Kerberos, but my MOSS web app using NTLM.

I have K2 blackpearl farm that used Kerberos as authentication provider.

I want to create a new web application in MOSS 2007 using Collaboration Portal as its site template, but this new web application will use NTLM.

My questions are

1. Can I use my K2 blackpearl to create/run workflow in this new web application? If the answer is YES, what should I prepare to make this things work (special configuration/setting in K2 and/or my web app)?
   
2. What is the downside of K2 blackpearl when handling this configuration (Kerberos to NTLM, or vice versa)? Security or performance degrade maybe?