My 2p:
- forget IPv6 but do NOT disable it from the network stack (as Microsoft places great faith in it and uses it in a lot of internal communication for processes which get their knickers in a twist if protocols are missing). You may need to kow about IPv6 shortly, but it's looking more and more like you'd only ever need it at the router level rather than on a home network.
- homegroup is fine, and is basically akin to "domain networking for dummies". It's certainly got just as many quirks and workarounds as workgroup computing, and there's a lot of FUD spread on threads such as this as to the effects of something people don't know too much about. e.g. Keef's drive locking would only be related to permissions needing resetting at the root, which is the same for any Windows box in certain aspects.