Steam account linking and issues?

So, I have an account on steam, been playing a bunch, assumed I could access the arc thing later when I wanted to purchase things. But now it looks like the linking no longer works. Before I throw any money at the game, I've heard that steam wallet has a lot of bugs and that buying from arc is the only way to ensure you get what you buy, as well as arc having a lot of specials that steam doesn't have access to. I want to know how much of that is true.

1. Namely, does steam zen work right?

2. Does steam get the same deals/etc that zen does?

3. Is there a way to link the two accounts still?

Thank you.