Latest Opinions on Assault/Defend PBEM Ratio

[zeiss]

I would find it very odd to always exclude VH hexes.

Yes, but there are plenty of other hexes to mine. The VHs are very inviting because you know the enemy must go there.

Do you consider placing a 3-hex deep minefield around a VH a valid tactic?

In fact, mining VH's deters a far worse gamey tactic and that is the last-turn VH grab using fast units by the second player (if that's the attacker).

It will certainly not deter the second player. Minefields or not, he has nothing to lose and will happily gamble his units for a VH. That's the whole point of the "last-turn VH grab".
A better solution is to always have the defender as player 2. (Which incidentally would deter him from mining the VHs.)

Although any player who lets me attack with a 2,0:1,0 advantage could mine anything he wanted.. ;)

In practice I still think the attacker needs a lot of terrain augmented by a little well-placed smoke. With SPWW2 smoke loadouts, ..very difficult to make it last long enough to cover an entire advance.

I think you're underestimating the smoke loadouts. Infantry and some vehicles also add to the pool of smoke. And you can't expect to play all your battles as a defender on the Keflavik airbase map. Your opponents will eventually become suspicious.. :)