I think that's a good start, and would generally work, but eventually you'd run into problems.
1) There is a period of time when both of your doors are open at the same time, because open signals propagate faster than close signals. This is 100 ticks, plenty of time for a dwarf to get across if it feels like it.
2) Not being familiar with that latch design, I'm concerned about its speed of operation, and vulnerability to being retriggered or toggled too soon. I would use something like
this one-- it's pretty much instantaneous, doesn't rely on flow (although it needs power), and is set up for the right kind of signals you're sending it. But thanks for the link to that latch, I'll play with it a bit.
3) Food attracts vermin, vermin attract cats, cats kill vermin and leave it in doorways of logical circuits.
I would probably do something similar, but it worries me the way you have the entrance set up-- I can imagine things going wrong with that set up, and the dwarf triggering the latch before he brings the food, getting caught in the middle and transferred between burrows. You can fairly easily make it one way:
#######
#^h^###
###d=d
# h^###
#######
which is probably how I'd first approach it. To prevent dawdlers coming along for the ride, I'd probably latch up the entrance hatch as well.
Actually, let me revise that a little bit. To prevent the problem with the doors being open at the same time, I'd make it more like:
#########
#^h^#####
###dh=dh
# h^#####
#########
When the door on one side is open, the hatch is closed. This gets rid of problems due to the difference in open/close signals-- even if it takes 100 ticks for the close signal to reach the door, it's not a problem, because an instantaneous open signal has reached the adjacent hatch. Actually, because delay isn't an issue, I might use raising bridges/retracting bridges in pairs instead, as that way, vermin wouldn't break the system (unless they landed on the stockpile square).
EDIT: duh, two bridges wouldn't work, what was I thinking. Well, they'd work if you used retracting bridge over ramp to block access, but that's unnecessarily complicated. Raising bridge and retracting floor grate would make good pairs instead.