Playing without losing coins is what already happens in PvP Duel. Adding bets to increase a reward when you can control who you face is very easy to abuse (note that you can create a second account and normally the electrum amount that goes to the winner is more than what the loser loses).
Yes, but the system now is easily abused. Take a deck, go farm, mess up your score, go hit pvp and even though it's random your score multiplier and electrum pay out are far greater. I've had days where I've pvp'd the same guy multiple times in a row at random. His score was multiples below mine, so my reprimand for losing was also greater. Even though his deck was far better. After hitting this guy 5 times in a row, I stopped for the day. Every system has abuse issues that need to be worked around. One solution could be minimum buy in. You need X 
to buy into a game where is the minimum bet. And you can't bet above Y . This could also work to be a members only feature. All just ideas, of course.
I think that if you beat someone with more score than you, you get more electrum than the other way around (or was it score gain? I don't remember). Everyone pays the same amount to enter the game though.
yes, which stinks when you play somebody who has a negative ratio because of FG farming and you have a positive ratio. So the
payout isn't quite as fair, I think it also goes to score modification as well.
