1. If you are starting out, imho French Lace is a good option. It is simple, durable, and looks natural. Later you can experiment w/ Swiss Lace or Thin Skin if you like (both of which are less durable than FL and need replacing more often, but are harder to detect). I started with FL 20 years ago and have never switched.
2. If you are using LH, perhaps a custom JQ449 is a good choice. S7 looks good too, but JQ449 has a poly perimeter, and will probably be more durable. But of course all of this is a matter of personal preference.
3. All systems require some form of attachment. I agree with the previous poster, tape is good with French Lace, Thin Skin good with glue. I like French Lace with tape only. I also like to have them attach clips to the poly perimeter for further attachment to my growing hair in the sides and back (which you can request on your order form).
4. I never heard of a hair system causing any kind of damage to follicles. I also understand baldness is genetic and caused by your body converting testosterone to dihydro-testosterone. I would avoid hair transplants since if you continue to bald you will end up with visible plugs, plus the thinness caused by the transplant. All they are doing is surgically moving hair from the back and sides of your head to the top and front. imho go natural and use a hair system.