Now, this is where it gets fuzzy: does this mean that as long as I book 14 days in advance and that there is space in *any* booking class in the Economy cabin, I can use my coupon? Or, option 2, does it mean that a certain booking class has to be available at the time of booking for me to be able to use the coupon?

If it’s the first (I can use my coupon irrespective of availability of specific booking class) - then it’s a good deal. Because I’d pay only EUR 160 per flight even on days where flights would otherwise be more expensive.

If it’s the second, then it’s probably less of a good deal, as I often travel around peak fare periods, where lower booking classes are sold out. If then I cannot use the vouchers I bought before the entire thing is pointless.