Completely overwhelmed by Remix can anyone offer advice/answer some questions?

I'm not a new player but I've not played in years (after years of playing). I know that my priority should be getting a character to 80 because that will help alts level somehow. I read the WoWhead article on the event. But I still have some questions.

1. Is there any benefit to getting the other artifact weapons if you have no play on playing those specs?

2. Are there any dailies I should absolutely be picking up every day? At the class place OR at the market place where you buy stuff?

3. Will just doing quests and dungeons be fine? I will be playing solo or with 2 other people so don't plan on doing raids. I am mainly interested in buying mounts or pets, don't care about transmogs.

4. I'll be leveling my main (a warlock) in group that will at least have a healer. I know hardmode is supposed to give you more bronze, when can I switch to hardmode? I didn't see the option on my level 15 near the guy in the market place?

5. Should I be getting professions?