1 - At 30, Ammo should be fine - Its well balanced and social enough not to cause too much disturbance to them if they are similar age. Younger guys seem to have stronger responses. TUTH however is more overt, so can make them draw breath. IJ is the most unpredictable and most likely to produce challenging behaviour.
2 - Yes, once you have your effective dose, it should be fine. More generally, it is a good idea to have regular phero free days anyway. Just to keep in tune with yourself.
3 - IJ has five times the none content of standard TUTH or Ammo and its steering not as determinedly sexual as TUTH. IJ seems to try and replicate aspects of an all-round assertive/abrasive personality.
4 - Yes. Mones hit hardest in confined situations. Cars are excellent and you may even want to reduce your doses if you are going any ddistance with someone (personally I love oils for their slowburn effect in cars! 
). If in a club-type space, just look to the couple of meters around you for effects.
5 - Depends. Younger guys using TUTH seem to benefit from it being under a light bit of clothing but for most others, I’d look for the best blood flow and open skin for maximum diffusion. This may help: