... on my solution
The principle of my solution is nothing more than treating the TXML as a custom monolingual XML filetype, and it's processing a file that has already been segmented in Wordfast so Studios segmentation should be irrelevant I think... unless you are using the Studio TM for export to TMX and back to Wordfast for some reason maybe. Or am I missing something here?
On the processing of tags... it's quite possible some tweaking of the filetype might be necessary but seeing an example might be helpful and maybe we can offer some advice?
On your earlier point...
1. Trados Studio will automatically and correctly localize the financial fields ( converting, from EN to FR in this case, 12,295.50 into 12 295,50 ). A great time saver. BUT the effectiveness of this method is limited by the fact that none of the financial TUs are saved in the TM.
Studio only needs the first number in a situation like this because the rest are autolocalized and are not coming from the TM. So maybe you are trying to use the TMX export in Wordfast and are then not able to see the same benefits because Wordfast needs them in the TM? I don't really know enough about Wordfast to know if this is the way it works but it sounds likely.
Maybe we will see a proper bilingual TXML filetype in Studio through the OpenExchange in the future.