Hi Dustbin, when doing your dmt internship ask whether the dive shop will limit the number of dives that you do on the course, many will limit you to a max of 60 dives - ideally you dont want any limit. It's also a good idea to ask how many people are likely to be doing a internship at the same time, oyu want as much experience as poss so if there's loads of people there doing an internship you might not get as much experience. Also, see what reaction you get from a dive shop when you ask them for info, if they are helpful and friendly in replying that is a good sign as you will be working with these people for a fairly long period of time.
If you are looking to do your instructor course after finishing oyur divemaster course it may be a good idea to do divemaster course somewhere that does the idc too as you will gt to know all the idc staff before starting your instructor course. Alternatively, you may want to do the divemaster and instructor courses in different places to get more experience of different dive sites / conditions it's upto you really.
As far as Ive seen, it's norm to pay for your course, I've only seen a few examples of companies that let oyu learn for free and then work for them for free for a period of time after. The shops that do this Ive seen were either in Cairns (Australia) or Protaras (Cyprus).
Message me if you need any details.
Greg Jenkins