I need some help figuring out whether I've messed up my new N800.

When it arrived yesterday, I immediately installed the latest version of the OS. Then, I set about to install Phil Langdale's modified kernel. I followed the instructions in the wiki article "How to flash the SDHC kernel w/out connecting to a computer," but I stupidly followed them literally and installed the sdhc-kernel-3.2007.10.bin kernel. Surprisingly, the N800 seemed to work fine.

Within minutes, I realized that I should have installed mcc-kernel-4.2007.26.bin. I did so. The N800 still seems to work fine. I have two questions:

1. Does mcc-kernel-4.2007.26.bin completely replace the pre-existing kernel, so that I can be confident that I have an intact, non-botched kernel now in place?

2. How, exactly, does one "reboot" the N800? I've assumed that this is done by holding down the on/off key long enough to shut down the machine, then starting it up again. Is this right?

Thanks to all for the wonderful help and guidance you provide in these forums.