After fiddeling around with the TM programming software I found the best way to activate TrackIR (view controlled via head movement) with only 1 push of a button while getting perfect mouse control if off - it's quite easy but been flying a less perfect setting for half a year now... just wanted to share!!
Rem -------------------------
Rem Views
Rem -------------------------
BTN H2U Toggle_Zoom
ANT 3 Zoom_In ^ Zoom_Out
BTN S4 /P < View_Mode_Pan KD ({Move_TrackIR Activate_TrackIR}) >
/R KU ({Move_TrackIR Activate_TrackIR})
BTN H1U Default_View
BTN H1R /H Move_Right
BTN H1L /H Move_Left
...
View_Mode_Pan: AH command for PAN viewing mode (F8 default)
Default_View: AH command for default cockpit view (F1 default)
Activate_TrackIR: AH command for mouselook (Right Mousebutton default)
Move_TrackIR: NaturalPoint command for mouse control in "key-activated-mode"
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Have fun!