See that last part about Mythic + dungeons not having any kind of real lockout is what scares me. I raid in a semi-casual guild and the problem we've always had is that some members just don't have time to do extra things besides raid so the Valor system drove a wedge between many of our members because some of us had the time to do it and the will to do it even though we already outgeared that content for VP while several of those people didn't have the time to do so, which made the members who had the time to do so resent those that couldn't keep up and I could easily see a similar thing happening if these Mythic+ dungeons can provide raid level gear for everyone.
It just reminds me of the raiding Wrath model with 10/25 being separate lockouts, it made most people try and run both to get as much gear as possible which lead to a lot of burnout as well as hurt feelings for those who couldn't participate in the smaller raid. I'm all for the idea that the more you play the more you can progress your character in certain ways but I do worry that this will just end up causing a bigger divide between those who have a lot amount of free time to play and those who don't. I do hope that eventually they do have some kind of lockout either daily or weekly or something to that effect, otherwise I know several people in my guild are going to run those dungeons for days to get all the gear they want and will end up resenting those who haven't been able to do so.
Just starting off with a new character get gathering professions and sell the ore/leather/cloth/herbs you get as you level on the auction house, even on dead servers materials almost always sell really well. Once you've got a decent amount of gold learn about your servers auction house as much as you can, keep tabs on certain items and prices they sell at (certain addons can help with this) and learn to play it. Buy low/sell high that kind of thing, its can be risky and takes time to really learn what will sell at what prices but thats the easiest way to really make money in the game besides just farming. Just be smart about it, don't put all your money into one product by buying it out you could easily get screwed over super quick doing so.
This is pre-legion however, once legion comes out the meta and the marketplace will massively change for the first few weeks.