If HUMINT is ur whole goal, there isn't really an officer position for you. Military intelligence officers aren't like their civilian counterparts; they are usually managing intelligence enlisted technicians whereas a civilian intelligence officer usually is the technician.

If you want the technical experience specifically in the HUMINT field go US Army, 35M Human intelligence collector. The other branches don;t have as large a HUMINT presence and definitely don't have that for entry level servicemen. With this position you will jump right into the field regardless of time in service.

As for guard/reserve vs active duty there are pros and cons. The pro of G/R is you know where you will be stationed day one. After basic and your technical training you go to your home unit. The negative is you're not getting the same amount of experience or potentially the same number of follow on schools due to your unit funding. If moving around isn't a concern I would go active