Regarding export from TMG of witnessed events: the ability to connect multiple people to an event such as a census record (instead of having to re-create the event for each person) is one of the features that has kept me with TMG for so long. I noticed last year that my exported GEDCOM file was missing the witnessed census events, and explored this problem with TMG support. Their response basically was "too bad".
I will probably move to RM, because it has this ability - but not until I have the time to re-enter all the census events.