Quote "As for using 'NameVirtualHost *', yes, this works fine if you only intend to use one virtual host."
I use 'NameVirtualHost *' and yet I have no problems despite having set up 12 virtual hosts. From my experiences explicitly naming 127.0.0.1 is not necessary. I could be overlooking something, but it does not seem to be affecting any aliases, though the only ones I have are the standard icons and manual aliases which are there by default and they work fine in all of my virtual domains.
You mentioned there would be problems using "other projects in your Sites folder *without* using Alias or VirtualHost". What do you mean by this? I don't have any problems with the sites folders in /Library/WebServer/Documents or /Users/userName/Sites by going to localhost or localhost/~username. If we don't specify 127.0.0.1 which virtual host are we sent to? Am I missing something because everything at least seems to be working just fine for me.