I will now put each suggestion in an answer to this question. Feel free to vote on each answer
human and human-skills synonym of physiology
rape synonym of sexual-abuse
fluoride synonym of fluoridation
congress synonym of united-states
cigarettes and smoking and perhaps nicotine and/or tobacco (not sure which should be the main tag)
programming-productivity synonym of productivity
We have medications and drugs should they be merged? We also have recreational-drugs and pharmaceutical
We have money and currency should they be merged?
we have heart-attack, maybe we can make a more generic cardiology tag?
cell-phone and mobile-phones seem like they are half merged. They are listed on the tag synonym page with pending (1) next to it.
I question the value of the following tags: time, causality (seems too much like a meta tag to me), force, lifestyle, networks
I am also questioning the need for both teeth and dentistry.
Feel free to disagree, discuss and comment