Usually I'm trying to get a dollar amount so they'll deliver for free. I think most of the suppliers I deal with are about $600, which unless I screwed something up isn't a problem. I haven't had anyone give me any crap about surfacing or straight edging though regardless of quantity.
Things sit for a bit typically. It doesn't take long for glue to tack up and be good for going through the widebelt though. I also don't pull the door out of the clamp until the next one is ready to go in either. That gives it a minute or two to sit with pressure on it.
I really dislike that door clamp. It doesn't mash things together hard enough for my taste. I'm running on a lower pressure here than I was at the old shop, and the performance has really fallen off. We end up putting a pipe clamp on a lot of doors because of it. I'm hoping to replace it with a JLT rotary door clamp this year. I really don't want to buy a new one as they're over $20k, but they don't come up used very often. The only one currently available that I've found is in BC. The price is reasonable, but I don't know what the international shipping requires, or costs. It's also REALLY far away.
The nails just get puttied. Whether stain grade or painted. That door just went into the dumpster after I made it. It was just for the video.