At the moment an update is not an update per se but a full install. This is tedious. Please reduce the *update* process to zero clicks (ideally) - think about the way Microsoft update individual components, you don't have to do a full reinstall for every single Windows update, you just get given the whole lot as a single zero effort batch job.
"Enter language for install" - irrelevant. This will be identical to the install option chosen (or do you really think that I want to install 2.15 in English, then 2.16 in German, then 2.17 in Chinese, then 2.18 in Afrikaans…? What proportion of your users do you think are really going to want to do that?).
"Keepass is running - shut it down first" - no, just send a shutdown command yourself. You should know how to do that.
"Start Keepass?" - Also irrelevant, this is an update remember, not a full install, so do this automatically. If you want to be slightly intelligent, don't start it if it wasn't running in the first place.
Here's my ideal scenario. Start Keepass; it detects an update, then says "Update available, do you want to update?" User then clicks Yes and the download starts in the background while normal functionality is available (or better still, when an update is available, download it silently THEN prompt for update), then IF it needs to restart, just pop up a message to that effect.
I have lots of apps on my PC and for every single one of them to demand the full installation process on every tiny little point update is really tedious. Actually what this means in practice is that I switch off the update detector.
KeePass is one of the most important pieces of software you use and should not be updated silently - what if you are in the middle of an edit? Updates are not to fix security holes (unlike Windows updates) and you do not need the latest version to be able to use it safely.