4. Are there jobs that pay btc?
Welcome to the club! There's a lot you could learn but not a lot you have to learn to start participating. The key thing to remember is that Bitcoin is a currency. It's not something that can only be earned in the Bitocin ecosystem, you can earn it in whatever way you earn money. All you have to do is either (1) ask to be paid in Bitcoin OR (2) take what you've been paid, in whatever currency it may be, and use it to buy Bitcoin.
Seriously, it's that simple.
If you want to convert some of your regular paycheck to Bitcoin there is a company that will do so automatically, from your payroll payment, but their fees are high and it's not necessary to pay those fees when you can just convert your paycheck pay (or a portion of it) to Bitcoin on your own.
Where do you live? That impacts some of the bitcoin exchange (and purchase) options available to you.
Its not easy to earn significant amount of bitcoin for free these days where price is over $4000 per bitcoin, nobody will give it to you for free. Get some skill like web development, photoshoping, signature code designing for signature campaigns in this forum and than offer your services in service thread of this forum, you might get few clients who will be willing to pay you in bitcoin for your service. Good luck..
I don't think you know the definition of "earn". Earn means doing something in exchange for something else. No income is free...it costs your time, knowledge and work.
And it's EASY to earn bitcoin...because whatever you do for a job you can do and request to get paid in bitcoin.
If you believe you can only earn bitcoin from bitcoin-based companies you don't understand bitcoin.