@Mark3602 You can't without incurring penalties. If you want to be able to communicate with guests before pre-approving or accepting their booking, you need to turn off the Instant Book function so you only receive inquiries and booking requests.
Instant Book reservations are exactly that- a guest just clicks on "Book" and they have a confirmed booking. It overrides an inquiry or booking request.
An Inquiry never blocks the dates- you have to do that yourself, so if you are speaking with a guest and want them to have the opportunity to book once you work things out, you have to block the dates until they are ready to follow through on the booking or they can be booked by someone else.
But be aware that many Inquiries do not follow on to book- they take up your time answering questions, then you never hear from them again. So it makes more sense to leave the dates open, so another guest who is ready to commit and pay, can.