Hello,

About the datetime picker, iCagenda is using a third party script to generate this date and time picker.

Currently, it's not possible to remove the time, because database is not able to manage it (and it would give errors).
Just to add as info, that i've planned a new save in database of the dates, and i have already started to work on a split of the date and time field. This is a long development i'm doing in parallel of the current version.
As only half of the code refactoried for this, it is not possible to add this now, but in a few months (don't know the number of months needed, as still a lot of work to do, but it's the main major change to be done in 2015)

About the frontend submit an event, what is missing, and could be done soon, is a global option to hide or show the time by default.
I will add this in my todo list for one of the 3.4.x release

Regards,
Cyril