but it was important to see dantooine again, what happened to it after the bombings of it, and there is much more significance to it was well, the crystal caves, revans footsteps, the jedi enclave and finding vrook one of the msot important master in K1
it was mentioned like once - leia said in episode 4 that the rebels where on dantooine instead of alderaan
dantooine was diff. to yavin, yavin was more forrest, jungle if you will and yes like you said temperate and swampy with a bit of variety not much, similar in ways it had temples with ties to the darkside, the war with exar kun and all, it would have been good to gone there to pick up all the stuff and see who inhabited it - like the rodian on that space station said.
alderaan was, like you said a bit like coruscant and taris huge developed city, so i doubt they would have chosen alderaan - its not that significant
and an ice world wouldnt have been too bad