I would be happy if the Geobra engineers made it easily possible to remove the new RC units and if they or Marklin could provide a replacement engine with track pick-ups. The engine replacements were in the add-ons at one time but didn't LGB make that part and Geobra made the shell?
No, only the rails were made by LGB.
I must disagree about track pickups, too. Firstly, health and safety rules in Europe would limit sales of these as mains powered train sets are seen as for the 14+ age group. Whether you agree with this or not, that's the way it is.
Secondly, power through the track is too unreliable, especially if sets are used outdoors (and with the size of G gauge, this is where they tend to be used). I'm on a forum called gscalecentral and I often read about the problems with bad connections, dirt on the track and stuck switches, which make me very glad that I use batteries and RC.