Except when you drag an app to the waste basket in OS X, it doesn't really delete the app in it's entirety. Many times, many files in OS X are left behind like preference files or other settings. This is similar to past complaints about un-installing an app in Windows (where the un-install doesn't clean up the Windows registry). In fact, I would say deleting an app by dragging it to the waste basket in OS X is worse (in terms of total removal) than un-installing apps in Windows. At least in Windows, many apps have un-install utilities that appropriately clean everything.
I agree, but you can download a disk cleaner which I run once a month just to free the disk from this kind of files...I agree they could do better but I prefer this solution to the Windows one.
* OS X's version of Windows Explorer is called Finder and Finder is very hard to become accustomed to. If you enjoy organizing your file system (to organize photos, movies, music, documents, etc into folders), you'll find using Finder very cumbersome. Finder doesn't provide you with the ability to navigate your file system's entire structure while looking at the contents of a folder - which means it's difficult to jump from one folder to another to copy/paste/move files. NOTE: Yes, I realize some people will say: why even bother organizing your files? Use iTunes, iPhoto to manage your files...and for those types of files, I agree. But I use my Mac for work and I like to organize my Word, Powerpoint, Excel files into folders for faster access.
To me it's like the manual vs automatic gear box "problem"...for most people automatic is better! But I can understand the will to control everything and "know" your machine better!
I also don't agree with the rest if your comments concerning contextual menus, but I guess I got used to it through ubuntu before switching to OS X...
The one really annoying thing about OS X to me is windows management (no word play intended)..drag and drop, like in the 80's...I can't find a single smart feature concerning this aspect of OS X!