I embrace full flexibility when it comes to work. Having worked in 9to6 jobs for nearly all my life, I realized I am much more productive when I can adapt my work schedule to both my customer and life schedule, allowing to maximize my work motivation and results without compromising the delivery date. That being said of course we can work a time schedule that allows for excellent communication between everyone involved.
I rarely check emails but I am always available from multiple communication tools like whatsapp or skype.
For payments, I rather work in milestones but every step must start with a clear scope document where everyone understand that will be done, delivered and all the responsabilities for everyone.