MOQ,
Lovely post, but your assertion fails the logic test.
But I must say, you and Captain Nomad are doing an incredibly thorough job at probing and examining the rules. So well have you done, that you have constructed an understanding that actually makes the various references all look consistent and without contradiction!
But alas, there are two big problems:
1. The logic test has failed. Under your assertion, a flight in the middle of the day, with 8 oktas blue sky, must plan an alternate if the destination has an IAP but no TAF. There could be another aerodrome a couple of miles away, with no IAP (and no TAF) but it wouldn't require an alternate - according to you.
2. Your assertion applies equally to VFR flight - and is utterly non-sensical when so applied. According to you, the VFR cockie needs to find out if his destination has an IAP. If it does (but has no TAF), he must then carry alternate fuel to an aerodrome that doesn't (or has a TAF)!