Problem is stats like GIDP are entirely situational and not really a representation of a player's true ability. And E's especially are entirely subjective and the reflection of one person's opinion- the official scorer. E's also skew the league away from MIF/3B/good players who play tough positions and commit more E's- if I was in your league, I might not spend on guys like Odor (good fielder, but second most in E's), Corey/Kyle Seager (Top 10), or even Arenado (Top 30) and instead focus my resources elsewhere. I just don't think there's a good way to score fielding in fantasy, so I keep it out of my leagues altogether.
If you want to objectively score players according to their ability- which I think is in the true spirit of the ottoneu game- then you should want to keep stats that are situational/team-influenced/subjective such as these out of your league. Of course, I say this while still using things like SV's, HLD's, BS's, Total Batter's Faced, and Inherited Runners Scored in my leagues as ways of balancing P production both with between SP's/RP's and between Hitters/Pitchers... so I'm not perfect, either.
On Coupons- I'll award $1 to the highest scoring team in the league for each week of the season, plus $3 to the divisional winners at the end of the regular season, plus $10 to the Bottom-4 scoring teams and $5 to the Middle-8 scoring teams (and $0 to the Top-4 scoring teams).
Coupons can be used on the arbitration increases of players only. We have both an Allocation system (using Bonus Cash, owners can increase the costs of other team's players at no more than $2/player and $3/team) as well as an Automatic Arbitration scale where the Top 50% scoring Hitters and Pitchers (separately; so 120 Hitters and 120 Pitchers in my league's pool) will increase in cost by $1; the Top 20% of scorers by $2; the Top 10% by $3; Top 5% by $4; and the Top 1.25% (or the Top 3 scoring Hitters and Pitchers) by $5.
If a team does not use their Coupons, then it becomes Bonus Cash which can be used either on Keeper Buyouts (players chosen as Keepers and then released during the season have a Buyout cost of 1/2 of their Keeper Cost), Arbitration Allocations to other team's players, or as a bonus on their Keeper Soft Cap prior to the next season's draft. Bonus Cash can also be earned by saving on the FA Acquisition Budget during the season, or by saving under the league's baseline Soft Cap prior to the season (basically, the League Baseline Cap is 1/2 of the Draft Budget; the Team Soft Cap is the League Cap+Team Bonus Cash; going over the Cap is a tax on the Draft Budget; going over the Cap and then ending the year with a negative Bonus Cash balance will result in a Hard Cap (League Cap+negative Bonus Cash) the following season).
Yahoo doesn't make it easy to run a league with a salary cap, and I've found that people tend to spend their resources differently in Auction Drafts versus in-season Free Agency- so I use the Bonus Cash/Arbitration/Soft Cap/Keeper Buyout system as a quasi- economic pressure relase-valve, or a way of allowing for teams to take advantage of any savings while still forcing people to make the tough roster decisions necessary to keep the draft a worthwhile activity every year. Of course, I have to track it all off the platform and in Google docs, but it generally allows for an economic balance year-to-year- which, with the divisional schedules, contributes to an overall competitive balance each season.
TL;DR- I disagree with using GIDP/E's in fantasy, and my Arb Coupons are an additional strategic feature of the overall economic structure that helps to achieve my league's general financial/competitive balance