Buffett's allocation is for his wife. Who is currently 68 (and could be much older when Warren dies) and will presumably have at least tens of millions in assets if not billions (plus SS and MC). His allocation may not be the best for someone retiring at 30 with $500k.
This!
Concerning the house as an asset, no you shouldn't include the house you live in as part of your investment portfolio. Net worth = yes, in your asset allocation = no. If you sold your house to have income your expenses would increase because you would start renting. Your house is not an investment. Thinking that it is can give people a false sense that they have more investment assets than they really do, and I can't think of a single financial planning benefit to counting it as an investment. Your house is a use asset just like a car or furniture. Your house can appreciate in value, but that doesn't do you any good while you are living in it. If you sell it and then move into a cheaper property then you get the equity and you can put it to use. If someone planned on downsizing I could see treating the difference in prices as a cash inflow for that year. That is as far as I would go.
Now rental property is another beast. It is property that generates income and it should be treated as an investment. So if you own a ton of rental properties you likely don't need to a REIT to your portfolio.