I feel like a bunney for asking this question, but should one re seat the valves when de- coking the head?
Not if it doesn't need it.
You remove the valves, and inspect the seats and valves for evidence of burnt or pitted areas on the contact surfaces, which may cause compression leaks. If you are unsure about it, when you re-assemble the valves and springs into the head, put the head on the bench with the combustion chamber facing up, and pour enough ATF into the chamber to completely cover the valves and maybe even fill it up all the way if you haven't de-coked the chamber. Leave it overnight. If there is any leakage at the valves, you will see ATF has leaked down into the ports. And leaving the the ATF in the chamber overnight will also dissolve the stubborn carbon in the chamber that was difficult to get off with your soft bristle brush.
If the ATF leaked into the ports, you can do the valve lapping. Also, even if it doesn't leak, if your visual inspection shows that there are places which are burnt or pitted to the degree that it appears they will begin to leak soon after you put it back together, then do a valve lap.
IMO, unless there is some extreme budgetary limitation, it would be better to have an actual valve job done if it needs it. The stock valve job is pathetic, and the flow performance could really benefit from getting some decent multi-angle valve and seat work. The valve seats are the place which could give the biggest bang for the buck in porting work, and you don't even have to touch the ports. Just the seats and the back of the valve. Of course, I realize that you'd have to go to bigger valves to do any corrections of the flow angle in the bowls, which is what we do, but you can get a reasonable improvement with the stock valves and a better valve job, in a budget scenario. Heck, we have a budget head mod done to your head casting for $500 called the "Clubman head", and we can do our Mondello multi-angle valve job on any Bullet head, even with stock valves for less than half of that price.
The valve lapping is a cheap effective way to restore burnt stock valve seats and valves to working condition, but it doesn't do anything for improving the flow. If anything, it usually will hurt the flow some. A proper valve job with performance angles is not really expensive, and it's a lot better than just lapping the stock seat angles with compound, unless there is a serious budget issue or there is no desire for better running involved.