Good news, but it's isn't the best news we can expect as bitcoin fans from Uber, if they integrated bitcoin fully into the platform then it would be magnificent, However, they probably added it to tipping to gauge the interest and as long as they see it profitable, they will probably add it even as payment.

Depends on your view of things and your religion, Regardless of it being a sin or not (IMO depends on what money you are gambling in the first place, since using online earned money doesn't feel that wrong), Regardless, it's a very bad hobby that cost people ALLOT of money...

The easiest would be to buy them of course, considering it require nothing other than paying for them , Other than directly buying bitcoins, freelancing is the best source IMO, considering the pay is much higher than faucets and the work isn't that much more than it.

I guess the number won't be allot and not exceed few thousands (which isn't few, but compared to the whole bitcoin community, it is small), some of them are the older holder keeping bitcoins from a long while, others are newer investors ready to go into a high risk investment with $60,000 value investment right now.
Currently investing in BTC can yield unbelievable profit if another climb happen soon, but a crash in price is also possible.