I have been looking at them, as I have to do some flights with them. Flybe Economy Plus has the same seat as normal one-class economy, and just a voucher for a drink, and a voucher for a snack. Nothing special.
One plus point about Rewards4all is that the points are valid indefinitely, without expiry. They are valid, when it comes to redemption, only for Round Trip travel, across 1 flight sector. So, GVA-SOU-EDI RT would be 2 separate tickets. No One Ways. Didn't know about the lack of lounge access, if redeeming in Economy Plus. Are you sure about that?
As for the credit card, any points collected have to redeemed within one year after collection. Watch out for that.
Did EDI-MAN yesterday. While the Embraer flight was very pleasant, there was a hideous baggage problem at MAN. There wasn't enough staff to unload baggage for delivery onto the carrousel, so for a 11h40 arrival I finally got out at 13h30. Ridiculous. Sort of thing you would expect at a Russian or Kazakh airport, and wouldn't get.