But if you get paid in BTC, you have a bigger incentive to buy with BTC. For example, the small amounts I get from the sig campaign, it's pretty tempting to spend them on small purchases like a videogame. In steam, it's easier to pay with BTC than to pay with the regular credit card purchase. I have to get my credit card out, put the date and pin, get the card of the bank to put the 4 numbers to verify the purchase, and I need to load the credit card if it's not loaded so it takes a bank transfer too. It can be a mess. With BTC is just a click, of course, a click if you don't first have to buy it, then it's just stupid.
Yes.
To take advantage of BTC, you need to be paid in it, so the circle is closed.
But this is the vicious circle: bitcoin will be handy money, when bitcoin is handy money. This is a "symmetry breaking" problem, in a way: once you're in one equilibrium (that of fiat), it is essentially impossible to flip to the other equilibrium (that of bitcoin), because there is a huge "mountain of inconvenience to go from one equilibrium to the other one, but on top of that, bitcoin is entirely designed to be deflationary, which is, by itself, a "repulsive" for being used as a currency (you don't want to SPEND something that will grow in value, do you !).
But anyway, BTC will never be a proper mainstream payment system without segwit and lightning network, until then it's a better gold, and that makes it undervalued.
I don't see it as "gold". I see it as a financial speculative product, like complicated derivatives, that are too complicated to try to have any fundamental analysis of, and just play greater fool games with. The stuff the financial world is fond of, and has already cupboards full of it, 10 times the world economy. The kind of thing that exploded in 2008. This stuff is not under valued or over valued, as it is a speculator's token.
It is zero at t = 0, it will be 0 at t = t_something, and in the mean time, it goes sky high.