I have read the posts and tend to agree with most of them to a certain point. The 1st question you have to ask though is what does the CERT Team that I am trying to join currently using for communications.
It obviously isn't a requirement to have a Ham License just to be on a CERT team. Maybe they already have enough comm guys for ham radio equipment and it isn't needed. Perhaps they have a good foothold with the local emergency management agency or local fire dept to fill the comm needs with commercial equipment, either way the answer you need is what is the team currently doing and what is the team planning to do in the future with their communications. Maybe the team doesn't have anything beyond cell phones, maybe they have a cache of public safety radios they can access and a licensed frequency to use them on, maybe they have HAM radio, amateur repeaters, and APRS position tracking, I mean seriously who knows?? There is no standard whatsoever so you have to ask. If you want to do CERT, but your group uses public safety radios/freqs, then it wouldn't make much sense to study for a HAM license anyway unless you just simply enjoy the hobby.
On another note I have seen just as many inactive HAMS misuse spectrum as I have inactive CERT teams which are absolutely worthless in real disasters. I'm not knocking either one, but just because you have one or the other doesn't necessarily make you useful or dependable in an emergency.
As far as Amateur Radio in general, yes it does play a huge role in emergency response when your normal everyday communication systems fail or become overloaded. The Redcross uses them at shelters, I've even seen HAM radio guys sitting at firestations to assist in dispatching trucks to emergencies. If its all you have left then you do what you have to do.
So to answer the OP's question. How does a amateur license help you in CERT? It doesn't, unless the team you are joining uses amateur radio to conduct its operations on. Then it only will if you take the time to learn your equipment, get comfortable talking on the radio, and getting to know all the other folks in your area that have amateur licenses.
The solution we have found in my area was asking the local ARES groups to provide qualified folks who are licensed amateur operators, are passionate about HAM radio just for the sake of HAM radio, but who also have been through CERT training, and that are also passionate about emergency preparedness and disaster response.
Remember, the key to being a good CERT member isn't going out and saving injured people, or playing hero on the 5 o'clock news. Its about keeping yourself and your family, and maybe even your neighbors, from becoming victims in the disaster. Take care of your family for at least 96hrs (use to be 72hrs but that isn't always enough time for the FEDS to get on scene) following a disaster without any assistance from anyone. CERT is ultimately about taking care of yourself. Period. Everything else about CERT is less important. You approach CERT with that attitude and you will be satisfied with it. Go into it thinking you will run into burning buildings and do heavy search and rescue and play hero, you are wasting your time.