The Finder sucks, but it is fully keyboard-navigable, and you can rename files and do other things quickly via the keyboard. Just select the file that you want to rename and hit the Return key.
Regarding "not a very OS X solution", I would just note that a "power user" is going to be on the command line all day long in Mac OS X, like any UNIX. Terminal.app is very capable, iTerm is there if you prefer, and many more technical users on the Mac will be using more powerful Finder replacements like PathFinder (that have built-in slide-out terminal panes), or using the excellent D-Term, which pops up a HUD-style one-shot command line in the context of wherever you happen to be in the GUI.
Regarding "not a very OS X solution", I would just note that a "power user" is going to be on the command line all day long in Mac OS X, like any UNIX. Terminal.app is very capable, iTerm is there if you prefer, and many more technical users on the Mac will be using more powerful Finder replacements like PathFinder (that have built-in slide-out terminal panes), or using the excellent D-Term, which pops up a HUD-style one-shot command line in the context of wherever you happen to be in the GUI.