Hi,
First, sorry for my bad english.... you may try this as starting point:
https://stash.reaper.fm/33919/f1_test.zip
I like to start with the default.ReaperOSC and edit the Lemur- or TouchOSC-template.
Volume, trackname, track select and RTZ should work now and you may use this as an example for the other functions.
Also keep an eye on this part of the ReaperOSC:
REAPER_TRACK_FOLLOWS DEVICE
DEVICE_TRACK_FOLLOWS LAST_TOUCHED
DEVICE_TRACK_BANK_FOLLOWS DEVICE
DEVICE_FX_FOLLOWS DEVICE
Regards, mj