With a lack of responses from anyone with more cammer experience than me, I might as well jump in with my take on a couple of your questions. My knowledge comes from building my iron headed cammer, and that was from information I gained from either the Ford manual, or from Jay’s posts.
1. I removed the gaskets from the spark plugs, since like you, I assumed that the copper tubes would act as a gasket. So far, I have not had any problems with this.
4. The factory lash caps will work, but good luck finding a set. Plus they were for the 3/8” stem valves. I’ve changed my valves to 11/32” stem valves, so I had to source a whole new set of lash caps to suit.
5. I have not used the cam sprocket deflection method, I have just adjusted the tensioner bolt to 125”/pounds torque. Again, so far, the chain tension seems to be holding okay.
7. I did not restrict the oil flow to the heads, my thoughts are that the valve train needs as much lubrication as it can get. I also use the mod that Jay posted, taking a restricted feed from the front head oil passage to drip feed oil onto the tensioner and idler gear bearings.