Post 1 study on a controlled group proving that steroids cause any of health problems you have mentioned.
http://www.nejm.org/doi/full/10.1056/NEJM199607043350101#t=articleTopThe four groups were similar with respect to age and weight, height, and body-mass index before treatment (Table 1TABLE 1
Base-Line Characteristics of the Study Subjects.
). Acne developed in three men receiving testosterone and one receiving placebo, and two men receiving testosterone reported breast tenderness, but no other side effects were noted. The serum liver-enzyme concentrations, hemoglobin concentrations, hematocrits, and red-cell counts did not change in any study group (Table 2TABLE 2
Hemoglobin and Plasma Lipid Concentrations before and after the 10 Weeks of Treatment.
). Serum creatinine concentrations did not change, except in the testosterone-plus-exercise group, in which the mean (±SE) serum creatinine concentration increased from 1.0 mg per deciliter (88 μmol per liter) to 1.1 mg per deciliter (97 μmol per liter) (P=0.02). Plasma concentrations of total and LDL cholesterol and triglycerides did not change in any study group; plasma HDL cholesterol decreased significantly in the placebo-plus-exercise group. There was no change in the serum concentration of prostate-specific antigen in any group.
Not only nothing happened, steroids+workout group had better levels of good cholesterol after the study...
I know two guys who prepped clean to their contests. Both manged to get to very low digit body fat without use of any hormones. Of of them visited hospital due to cramps. The other one had serious health issues realted with cholesterol levels, testosterone levels and such. This shows how bodybuilding lifestyle itself, without use of any substances can be detrimental to your health.
Of course steroid abuse or long term use of high doges will harm your body. So will use of aspirin or ibuprofen over a long time. Actually, if I had to choose to use ibuprofen in recommended dose and testosterone at 500mg weekly for a year I would without any doubt choose testosterone.
Different steroids have different effects on the body. Testosterone for example can cause water retention which leads to hypertension. This can damage your kidney. Yet, if you deal if the hypertension nothing will happen to your kidneys.
What (nearly) killed Derek was homoerotic lifestyle with a lot of painkillers, narcotics and heavy steroids and synthol abuse. Diuretics are also demonized, it depends on a substance. Obviously lasix isn't something anyone would take except it is really needed (not many people I know used it because you can come in dry at the contest without it) and spironolactone can be basicly taken daily. It's sodium sparing and really mild, worst thing that can happen is killing your gains or man boobs (it's an antiandrogen). My ex girlfriend took spironolacton daily for years without any side effects except from very low blood pressure.