I'd move the front cameras down from the soffet and onto the overhang of the upstairs. That soffet is way too high to be effective in terms of identification, like Tony said. Mounting heights much over seven feet aren't worth doing.
I'd move one camera in the back to the other side of the house so that the fields of view overlap and watch each other. Again, move them down, they're way too high at fifteen feet. Consider another camera on the rear corner looking along the driveway out to the street. You're trying to cover too much area with too few cameras for them to be effective.
Skip the Nest, it's cloud based and a security hole as a result. If you really, really, really, want a doorbell camera given the inherent problems they all seem to have, look at the RCA 3MP model. It, at least, has an RTSP stream, cloud not needed, that you can access with BI or other VMS software. All of them, the RCA included, seem to require the naked eggplant dance, multiple firmware updates and different apps depending on exactly what you want them to do to keep them working marginally. Look in the doorbell thread here on IPCT to get an idea. I've been looking, and reading/heeding, what's been going on over there for months and have yet to find one I'd consider spending money for. Why a doorbell camera can't come standard with PoE and dry contacts for an existing chime is beyond me.
All that said, I know the WAF has to be factored in as well. So good luck with that! I also know that wiring a bi-level can be a real challenge which is another factor to consider.