Answer: Yes, in most cities. Water treatment in the majority of Europe is as safe or safer than in the US. Typically, it is not done; Europeans usually prefer bottled water or mineral water over tap water. If you find yourself in more rural areas, it should still be safe, but if you are concerned, the bottled varieties are always available. If this is not an option, you are still averse to drinking tap water in other countries, and you find you will be traveling Europe for an extended period, invest in an inexpensive water filter straw (available at most hunting or sporting goods stores).
Answer: In most countrys the landlord will only be responsible for water after it enters teh building. However, if the water quality is poor before this point then its down the utility company who supplies the water to te building. If there are issues you need to establish what these are, and where the issue potentiallt stems from. One good way to establish a potential area is to ask people NOt in your building if they are having issue i.e. next door. If they are not having issues and you live a apartments check with other residents - if these to see the same issue then speak to the landlord
Answer: depends on your level of activity, oveiosly the more you sweat the more water you need to take in. I believe that the maximum the average kidneys can filter though is 23 liters pre day. You DO NOT want to drink this much though as it will damage your kidneys. Research kidney function to find out how they work.
Answer: Yes, it is basically safe to drink. Tap water in Japan is treated with ozon or chloride. Amounts of chemicals used in treatement vary according to the quality of the water sources.
Tap water in mountainous areas (ex. Nagano pref) where small amount of chemical is needed, is particularly famed for its "sweetness". The water gets tastier recently in Tokyo where use of chloride in treatement is mostly replaced with other method such as ozonization.
In rare cases tap water can taste bad when the pipeline in the building gets rusty or the water tank of the building is badly maintained, for example the lid of the tank is moved open, letting everything from the sky to drop inside! In such cases boiling the water to have a cup of green tea might be a better option compared with just drink it directly from the tap, but just go find a bottle of water at a ubiquitous convenience store.
For some (particularly elderly) people in the country, tap water is believed to cause an obscure long term health hasard due to chloride-derived carcinogenic compound such as tryhalomethane and other chemicals and buy drinking water at the supermarket where water treatment machines said to remove such chemicals are installed. However, at least accute hasard such as epidemics of infection or incidents of heavy metal poisoning is almost unheard of for 30yrs.
Answer: If your water is naturally soft it is perfectly safe to drink.If your water has been softened by a "water-softener" it contains sodium ions as a byproduct of the softening process. Having an intake of this much sodium in your drinking water could be detrimental.
Answer: It depends on where you are. In major cities like Beijing or Shanghai, which are very modern and industrialized, the major hotels and businesses have safe drinking water, as do most of the homes of the middle and upper class. The problem is out in the rural areas, or where poor people live. In such places, there may not be a modern system of plumbing, nor a way to filter the drinking water to remove bacteria and pollutants.
Answer: Only if you want to have a horrible time. Even my ex, who was Peruvian but had lived in the U.S. 10 years, did not drink the water when we were there. Bottled ONLY. No ice (made with tap water).