From: Iowan in MD/DC
My R&D and production system is based mostly on strategic and operative values, with tactical considerations left to third place in importance. This means that plane types engines and service rating and time you get use from plane type (before being obselete or replaced with superior model) are more important to me than actual numerical values of type itself (which are not ignored, of course).
R&D at 6/42;
A6M5, B6N1, D4Y1, N1K1-J, P1Y1
Ki-43-IIb, Ki-61-Ia, Ki-67-Ia, Ki-84a
A6M5c, B6N2, D4Y3, N1K1-J, P1Y1
Ki-67-Ia, Ki-84a, Ki-100-I
A7M2, B6N2a, D4Y4, N1K2-J, P1Y2
Ki-84r, Ki-100-I(II), Ki-115a
I have noticed that predictions or plans extending after 6/43 will usually fall appart, so I leave planning to 43 only. R&D is concentrated to few models, which I concider vital (mainly bombers and fighters). Not all of these go to production, like Ki-61 or B6N1 and there are a lot of models that go into production, but aren't researched at all (why preform R&D for a transport?). I also don't think Japanese player will lose the war, if he gets H8K2 2-4 months later, thus recons, float-planes and patrols can use older models until the "natural" arrival date. Only D4Y1-C is close of being an expection, but need to R&D the engine and then over build it to get 500 pool has dropped that one from my R&D plan.
Kami models are researched (D4Y4 and Ki-115 are in plan) as Kamikaze is fearsome weapon for Japanese player and should NOT be preformed in some plane found in "the corner of the pool". Proper models for that job are the ones with 800kg bomb and decent pool numbers of those are in my mind essential by 1944.
Especially in Scen 2 the R&D numbers for the models are large and essential planes will arrive quickly. After the "1st Stage", end of 1943, every important bomber and fighter will be in service and R&D is freed to either go into production or start "super-plane" projects for the end-game, like Ki-74-I, Ki-94-II, S1A1 and such. This Last Stage R&D has little value for the game as whole, but might produce few surprises for the opponent (Ki-74 especially has some awesome possibilities built into it).
Production wise I divide the game into stage 1 and stage 2. Offence and defence. Offence production discards the Interceptor (defensive fighter) in favor of Air Superiority Fighter plane (Ki-43 vs. Ki-44). Stage two switches the roles (Ki-100 vs. Ki-43) and also drops the bomber production in favour of fighters.
I would like to point out, again, that the only difference between B6N2 and B6N2a is radar. And the B6N2a's radar will not activate until 11/44 regardless of the arrival date of the B6N2a, if my understanding of devices is correct (you can't speed them up). So while it might be worthwhile to research the 2a so that it arrives prior to 11/44 and you have a pool of them built up, there is otherwise no real benefit to researching it earlier than 9/44 or 10/44.
I think it's fine to use "corners of the pools" airframes for kamis. They aren't ideal, but if you're going to have the airframes sitting around anyway... Look at it this way: you've already spent the HI to produce those planes. May as well get some return on that investment, even if it's just eating up CAP ops points, right?
Also, the Oscar-IVs and such with their decent speed and 2x250kg bombs are still good kamis. Nates, on the other hand...if you're using them as kamis you're really scraping the bottom of the barrel, but you're probably in 1946 by then, right? So you won anyway!