If you live in the suburbs of any capital city in Australia the water from your kitchen tap is relatively safe (save for the intentionally added toxic chems in low doses)
When I say relatively safe, in relation to bottled water your tap water will have a considerably lower bacteria count.
On top of that, boiling the tap water will kill enough germs to make it completely safe (the water that is, not injecting) (...so long as you aren't banging hot water)
This is AusDD, and given that, everything you're saying about tap water only applies to people with rural water lines or people running off bore water which they would be aware of, or lines with recycled water which evidently still have a normal line going into the kitchen. I'm not here to talk about common sense and go into circumstances that apply to very few.
You can talk your bullshit variables, but if my words make no sense to you then I'd feel safe saying it's you and not what I'm saying.
If you need it explicitly explained, the order would be: unopened bacteriostatic, unopened sterile, boiled water, kitchen tap water (for metropolitan australians), bottled water (which almost always has a higher bacteria count than first world tap water), hot tap water (doesn't get hot enough to kill bacteria, so the constant heating and cooling in the tank facilitates bacterial growth), toilet water, spit piss puddles and fruit juice, shared water sources.
Once again, your variables on taps does not apply to AusDD as I would bet $1000 any bottle of water you find at the shops will have more bacteria than any tap kitchen tap you use in the city (again pH can be an issue for some, but it goes against HR to use bottled water unless you're rural or running on bore/rain, or live in a country that isn't Australia, in which case you should know the water referred to in Australian specific forums would vary from your own.
I can't believe I had to explain this.