MissC
At AF, you call BN RAD 125.7 for TXP code prior to taxi. You then call AF SMC 119.9 with GAAP IFR taxi call. If in VMC on departure use VFR departure as per ERSA and contact BN RAD 125.7 for TXP identification and clearance as per ERSA; departing in VMC thru YAMB airspace when active contact AMB APP 124.6 crossing the Western FWY. If IMC departure via SID, just do as you're told! Using a VFR approach point when in VMC helps everyone (nothing different here!). AF tower very helpful to IFR and will offer you most convenient (i.e. least taxiing) runway if available.
PF and MB tower give you code with taxi call. Conveniently the inbound track to MB from ELW aligns with VFR approach point ACE (Academy).
If not departing on a SID you either follow such instructions as given or depart at the stipulated circuit departure altitudes and then require clearance to enter CTA.
BTW - if weather's crappy, YMEN's ILS will get you down and is more convenient than YMMB for the city and hire cars, etc.