Hi there, sorry for delay, looks like I wrote an answer and then it did not upload.
Yes, all Fanatic/DT parts fit together and can be mixed. Since the AL3.0 the Windsurf and SUP/WING wings also have the same front mounting system, which as been the same for SUP/Wing since the very first version.
Correct, yes the Duotone foils are 2024, there are a few which simply got rebranded like the Free/Lift, but also new ones like the Whizz which are unique to Duotone.
Any foil which has the same name, has then been updated from Fanatic to DT - Carve 2.0/Free, Lift for example - but the Free range is not the same as the HA, the Free is an updated version of the HA, with quite a bit more performance and range.