Are these chemicals suitable for disinfecting my water tank?
When you start asking questions about chemistry you are only left with more questions... in general terms of safety, using household bleach to create a concentration of 1 - 3 ppm sodium hypochlorite is relatively safe (especially compared with sewage). In specific terms, the answer is two-fold; you have to consider the amount of exposure and the component's toxicity (the difference between medicine and poison is the dose). 

It is important to note that the SDS for household bleach only lists sodium hypochlorite in the hazardous ingredients section. This directly implies that the only chemical of significant hazard in the bottle is sodium hypochlorite, and the rest of the ingredients are not present in sufficient amounts to cause issues.

First let's look at what thise things are:


Water : you know
Sodium Hypochlorite : bleach- household bleach is made from chlorine, caustic soda, and water and DC current (electrolysis).
Sodium Chloride : table salt, leftover from production or evaporation of water and chlorine.
Sodium Carbonate : washing soda- kind of like baking soda but about 40% stronger. This may be considered a buffer or stabilizer or byproduct.
Sodium Chlorate : when bleach is cooked/boiled (and dried), the leftover crusty stuff is salt and sodium chlorate... so this would be a byproduct, probably only in a very tiny amount.
Sodium Hydroxide : lye (caustic soda, NaOH) - household bleach solutions are typically stabilized by lye as part of the manufacturing process. Lye is used for raising the pH of drinking water and for making many things including soap.
Sodium Polyacrylate : thickening agent - It may be used in food, toothpaste, and shampoo.


APPROXIMATE Household Bleach Amounts: 


Water : 93%
Sodium Hypochlorite : 5.5%
Sodium Chloride : 0 - 2%
Sodium Carbonate : guestimating 0 - 0.2%
Sodium Chlorate : guestimating ~ 0 - 0.2%
Sodium Hydroxide : since the pH of bleach is about 11, the amount of sodium hydroxide must be less than 0.001 molarity, so less than 0.004%
Sodium Polyacrylate :  based on the viscosity of bleach and my personal experience with this thickening agent, about 0.5%.


Now lets look at the LD50 (a general measure of toxicity). The LD50 is the amount of material necessary to kill 50% of the test subject (usually rats). For these chemicals I listed acute (hard and heavy) oral dosage. Chronic exposure may be more relevant because you will not be drinking this, but chronic exposure data is also far more difficult to measure accurately, and with respect to all of these chemicals, chronic effects are generally nil, so I wouldn't have anything to say.


Water : greater than 90,000mg/kg, rat (yet drowning causes more deaths than all of the following chemicals combined)
Sodium Hypochlorite : 8910 mg/kg, rat
Sodium Chloride : 12357 mg/kg, human
Sodium Carbonate : 4090 mg/kg, rat
Sodium Chlorate : 1,200- 7,000 mg/kg, rat
Sodium Hydroxide : 100mg/kg, rat
Sodium Polyacrylate :  greater than 2000 mg/kg, rat. When something is above 2000 mg/kg the exact lethal dose is often not pursued.