My advice, bring as little equipment and/or try not to be too obvious that you are carrying photograhpic equipment.
Between Yogya and Surabaya, there is a direct flight. Otherwise its train (which i do not recommend).
Mt Bromo isn't in Surabaya itself its about 3 hours car ride away, and suggest you check in the night before and book in advance, year end its always full.
Withing Surabaya itself, I am not sure what you like to take, there is a "new town" based on Singapore, you might want to take pictures of Mini-fountain of wealth, Statue of Raffles, Huge version of Merlion.
There is an inactive Synagogue (not a spectacular building) of historical interest.
Cigarette factory at House of Sampoerna.
Hero's monument which is symbol of Surabaya.
The new SuraMadu Bridge is of an architectural feat (but there are better bridges around).
For man-made disaster... you might want to go Lumpur Lapindo or Lusi. Its a result of a corporate exploration which casued a mud flow inundating entire villages.