If you're a new player and buying gold (for some startup money) isn't an option, there's nothing wrong with gathering (especially if you're getting BfA...it'll be good gold initially if you farm BfA mats and sell high). You can make pretty good money just flipping stuff...and because Legion items are super risky now, it's a good time to get spirits of harmony (just buy what you can and sell it in in bigger stacks at higher costs or turn it into ore/bars or lotus to sell when that is profitable). I'd avoid putting all of your gold there though. Sometimes a bot or just someone returning to the game will dump 10+ stacks of 200 spirits cheap and tanks the markets for a bit. Flipping (if you get good at it) will make you more gold in than long run than farming but if you don't have much gold either is a step forward from here. They key to making gold is having the flexibility to lock up most of your gold in items and wait patiently to sell them at a good price but you gotta start small (or cheat like me...when I came back in December I just spent $100 on tokens and haven't spent money on anything other than the Collector's edition since. It's a lot easier to make gold if you already have some.
-Bugs- There aren't too many glaring bugs anymore, but you will certainly encounter some. The pathetic thing is that many of the bugs you'll encounter were reported repeatedly during Alpha/Beta and still weren't fixed. Some bugs were discovered after release and players were able to abuse game mechanics without repercussion unless they were one of the more serious offenders. This gave some players a significant advantage over others because they used exploits and at the start of an expansion, that is the time when it's most impactful.
Mythic+ rewards will also go up by 30 item levels; however, during the first week of Season 2, rewards from end-of-run chests will be capped at Mythic 6 quality (item level 385), and the chest you open next week will contain Season 1 rewards if you do a Mythic+ run this week. (So, for example, if you do a Mythic 10 during the final week of Season 1, you’ll get a Season 1 item level 380 piece and 60 Residuum from your first Season 2 chest.)