Views: making a week schedule + preventing overlap events

Dear Drupal community,

I've got an interesting project and have some questions about how to achieve the desired result.

The desired result: a week schedule where you can fill in something to want to hire (like for example a bike), the view has to look something like this picture (like a grid, you must see every hour and see when its hired). Also, when someone tries to hire it when its allready hired it must be impossible to hire it (error message).

So basicly the project consists of two things:

(1) A (views) week view where appointments are displayed hourly (like a grid, see pic)
(2) A check/validation so there is no double booking.

And so I've got two main questions:

(1) I use Views & watched Sean's video on views + calendar (great, thanks man!!). Now I have a week view but events show up filling the whole day and I cannot manage to get it better using css -> more has to be done... any suggestions??

(2) I do not have a clue yet on this one, do I need AJAX submit? Its only in developmental version yet, maybe AJAX Module can also be used (I think). Is this doable/what is the path to success!?

When I get this to work nicely, I'll publish either a short vid or a tutorial to help others!

Greetings Bas