I'm using KeePass Professional Edition, not KeePassX. Pretty sure they both use the same database format and are both cross-platform, so you should be able to switch pretty easily if KeePassX doesn't do everything you want.
For browser autofill I'm using the KeePassHttp plugin with ChromeIPass.
For InputStick I'm using Keepass2Android with KP2A InputStick.
Autotype is a built-in feature of KeePass on desktop.
Password database is stored on Google Drive, encrypted with a 2-part file and password based key. The file-based component of the key is stored locally offline on all my devices. Changes to the database get synced automatically by Google Drive on my PCs and by Keepass2Android on my phone.
I'm not sure about iOS, unfortunately. My phone is running Android, so I haven't really looked into KeePass clients for iOS.
What is KeePass Professional Edition? When I Googled for that the best thing I could find is "Professional Edition" on this page: http://keepass.info/download.html
Is that what you mean? It looks like it's written using Mono for non-Windows platforms. I might have shied away for that reason. What platform do you use it on? I'd love to know if it works well on non-Windows platforms (OS X, Linux).
Yes, that's what I'm referring to. I mostly use it on Windows, so I can't really comment on how well it works on MacOS or Linux. My understanding though is that it's basically a straight port, so most of the same functionality should be available.
Another option you might want to look at is KeePassXC. It's a fork of KeePassX, and it has built-in (though off-by-default) support for keepasshttp.
"so I can't really comment on how well it works on MacOS or Linux."
Linux: rock solid for several years now. We have several KP databases shared by 20 odd people that contain several thousand entries. I use it on Gentoo and Arch desktops. It runs under Mono plus a few extras to do things like sending links to browsers and autotype etc.
For browser autofill I'm using the KeePassHttp plugin with ChromeIPass.
For InputStick I'm using Keepass2Android with KP2A InputStick.
Autotype is a built-in feature of KeePass on desktop.
Password database is stored on Google Drive, encrypted with a 2-part file and password based key. The file-based component of the key is stored locally offline on all my devices. Changes to the database get synced automatically by Google Drive on my PCs and by Keepass2Android on my phone.
I'm not sure about iOS, unfortunately. My phone is running Android, so I haven't really looked into KeePass clients for iOS.