Avoiding Gotchas When Upgrading Kernel Via YUM

So I'm in the process of catching up our RHEL servers on patches and in the process, upgrading the kernel.

So far, so good. Except I've got one hangup that I'm working thru and have a case open on it. However I have some questions, and it seems almost too easy to run yum update kernel and yum update kernel-headers.

First question, is how do I know if an existing kernel is using specialized drivers and/or software? If it does, how do I know how to handle the update so it hopefully goes smooth?

Second, after I update the kernel, I'm checking under /boot for the latest vmlinuz, initrd and under /boot/grub/grub.conf to see if an entry has been placed under there. Is there anything else that I should be checking?

Also the previous admin wasn't enabling kdump. Is anyone using this to troubleshoot kernel issues when updating?

thanks