David Tennant was the first doctor I knew about, so I may be bias, but to me, he 'is' The Doctor. I often found Matt Smith's performance to be imitative of Tennant, but a lot more childish, which I did not enjoy.
Bright colours are easily visible, hence visibility jackets and wet-floor signs, etc., tend to be bright yellow. They will draw the most attention, but not necessarily positive attention.
It's more environmentally friendly to use bottles. There's really no use for canned water -- and yes, it's better to see what you're drinking.
Going on nothing but limited knowledge.
Not in the developed Western world; yes in undeveloped nations (generally speaking).