That seems way too easy to turn a strict neutral. Nations should be focusing more on fighting each other and not so much on strict neutrals during a world war.
What I’m thinking is that;
-You have to control an adjacent territory to attempt to turn a strict neutral
-You can only make one attempt per nation to turn it (in reality if you fail they would probably be p!ssed off at you and hang your spies)
-You have to roll a 6 to turn it. I like your idea of having to pay the number of IPC’s the territory is worth for failing, SS.
-You wouldn’t move into the territory, you would simply make it a pro-axis or pro-aliies neutral. After that anyone could move into it without violating Starfleet’s Prime Directive (or strict neutrality).
-You don’t have to be at war to do turn a strict neutral. Like all actions of “The Spy”, this would all be done covertly of course and denied vehemently.
As far as Research and Development goes, I would reason this by saying that your espionage activities have accumulated enough intel from both friends and foes and combined with your own research that you have a 50-50 chance of developing a weapon. How this would work;
-You roll 3 dice for free. A roll of 6 means you are successful. You only count one 6.
-If successful you roll the die for a weapon. You then CHOOSE which table to apply that roll to. That’s the way the rule should have been written in the first place. Why on earth would you ever spend your resources in the real world to develop a weapon that does you no good? Oops, we developed rockets, what were we thinking? It started out as a good idea to have Research and Development but then it turned into a really bad idea because the whole thing was left to chance instead of strategy.