Everyone needs to relax. Shenmue's story has been completed and done for nearly 20-years, and knowing Yu Suzuki there is no freakin way he would be like, "oh yeah, lets just cut chapters 8, 9, 11, and 13 because hey, the kickstarted only earned 6mil." This man had enough integrity and cared enough about this series to hold onto the desire to finish it for this long, and I know he is doing this way more for the fans than because he thinks he's be able to buy a house in Beverly Hills after this. The whole story, as it was intended will be present in Shenmue 3, I guarantee it.
The stretch goals involving the different locals explicitly say "extended" followed by the feature. This tells me that the current budget does not afford enough resources to add these things, but if we reach those goals they will be able to add them. It does not mean that Biasha Village will not be there if we don't reach 4mil. I am 98% certain it is the same for the other two areas that were shown in the Kickstarter video. Essentially this game will have everything we need to get the full story and experience it as we did in the previous two titles. Funding these stretch goals ensures that there will be even more content in each main area, which is definitely worth reaching these goals imo.