...Slash is very polite... I'd go a step further and tell Doh to go build his own version... the source is right here... because basically that's what you're asking for... a personalized version of the app.
first of all - look at the version number. 0.4.3 and past numbering 0.4.1, 0.4.2... it's very conservative because this app is still young and growing. You have to be realistic. Coupled with the fact that there's been a change in developers/maintainers fairly recently, I really don't see a lot that warrants intense criticism of this app.
1. Why should the lock file be invisible? I'd argue it needs to be visible for those who share a database file over the network with others, which, if you take a look at the Dropbox forums, might be a more common practice than you think. If I remember correctly, KeePassX throws a generic error about possible corruption in the file if a separate attempt is made to open a database already in use - and there may not be a way for it to throw a more accurate message like "database in use" because of the simple fact the application allows you to disassociate your database file from KeePassX completely, dropping the default extension, as yet one additional way of securing the database - by disguising it. All of my database files are identified in Finder as plain text files with innocuous names to be opened with TextEdit; there's no connection whatsoever to KeePassX.
2. If I had a penny for every app that doesn't comply with Apple's recommended protocol regarding the location of app preferences and app data... while this is an important topic, you just have to suck it up. If you don't like the default location and it's hidden visibility, set up a symlink that is more appropriate for you... I have a whole folder full of symlinks to the hidden folders located in my home directory (just about all of which are apps ported from Linux - Mplayer, Gtk, GNOME, inkscape) so I don't have to toggle invisibility on and off all the time... oh, and look... there's a .Xcode folder, .cups folder... me thinks those belong to Apple! And then there are people who pollute the Preferences directory - Opera is notorious - not only do they have an entire directory in Preferences, the directory contains things like bookmarks and notes... which aren't Preferences... and this is despite the fact they have a separate additional directory as well in Application Support.
3. Ok, I have to ask this question - it's about the status bar - for someone who clearly is in favor of slimming down what you think are unnecessary elements to the user interface, why on God's green earth do you have the status bar enabled? If you think the border is ugly, disable the status bar. I'm not sure what it's good for, except resizing the window, and I don't know about you, but KeePassX assumes application function designation of Viewer more than anything, and it's not an app I leave open and running all day long. I open and close it as needed to get a password. Fiddling around with the window would just slow me down. I set the size and forget it and turn off the status bar. (It is indeed ugly, but also useless and a space sucker on a MacBook.)
4. Why NOT have a new database button? What harm is there in having it? I mean, you can argue that for all of the icons in the tool bar and the same rationale would apply: there's already icons up there, might as well put another. The better option than arbitrarily eliminating icons is to allow customization of which items appear, which is common in Mac native apps - you can put every single command/function for some apps in the tool bar if you wanted. But this isn't a Mac native app - but who cares? As it sits now, KeePassX, of almost all its competitors, has the smallest memory footprint, is the most compatible cross-platform, doesn't cost one cent, and is actually secure.
Aside from that, you may not use the new database function very often, but again go take a look at the forums for Dropbox, there are a number of people using this app in enterprise for a number of different purposes. I personally myself use it to store all of the records for the domains I manage, serial numbers for software/hardware, credit card numbers, and because it allows for the attachment of files, I can save electronic copies of receipts in the same record that stores the serial number for my computer for instance.
5. If you have issue with localization, provide a translation. There's a link right on the home page.
6. You left out the uselessness of the "system tray" and "task bar" settings under preferences as well. LOL. I'm not sure I even know what a system tray is.
7. "Bump." What's that all about? It's rarely appropriate to bump a topic yourself, let alone on a forum as quiet as this one.
Now, hop on over to PayPal and send the dev some money.