When configuring the projects webapp directory (Project properties/Tomcat), I notice that there is a simple text field for setting the directory path. It would be desirable, if we could have a file selector box, or ideally even two (one within the workspace, and the other one externally). Much like when configuring the "Working directory" for running a Java main application in Eclipse.
Which configuration field do you mean in the properies dialogue?
I see "Application-URI" determining the path with which a webapp can be accessed on the tomcat. Second I see the optional field to configure the subdirectory serving as webapp root.
If you mean the second one I can imagine this to be a directory chooser for workspace-internal folders. I cannot really imagine a reason to select external folders, but I might be biassed as I never used this feature before.
Makus: IMO, it could be both (local, and external). The typical use case is a build script, which assembles the webapp in a directory. This directory might be located just about anywhere. I agree, though, that workspace-internal is the more likely, and more important, variant.