Although I, too, am not fond of the current command names, I'm not aware of a naming conflict that is serious enough to warrant renaming. Do we have even one example of one significant naming conflict?
Renaming executable seems likely to create much more confusion that it will solve. I loathe the idea of confounding years of newsgroup/mailing list wisdom, especially for newcomers. The specter of having to ask questions like "Which executable naming scheme are you using?" is also unpalatable. (Remember, this is the group that will engage in multi-message threads about postgres, postgresql, PostgreSQL, PG, postgre, etc. We'll need a new list for the fallout of renaming executables.)
Perhaps one way to sidestep this issue is for you (Zdeněk) to create a pgFoundry project that provides the command line interface you propose by wrapping the existing postgresql binaries. This would provide the more rational names you seek. Furthermore, it could be used to provide the *sole* interface to postgresql if postgresql is configured with a --prefix that sequesters it from system paths. In the meritocracy of open source, your interface might become the official interface later on.
I completely "get" your motivation and I appreciate your effort to tidy up. However, renaming is going to create problems, not solve them. (And, it's not even clear that there is a problem.)
-Reece
P.S. My responses:
1. a (do nothing) (or b if there really must be a change)
2. a (multiple times daily)
3. consistent with 1
4. c
Blue. No, red. Aaah...