If you think it's confusing going through your agent, why the heck do you want to cut them out? These real estate agents live on their cellphones, and if you aren't down with buzz-buzz-buzz, keep your intermediary.
If you want to make an offer at 86% of listing, by all means go for it with your agent, and tell your buyer's agent my following anecdote. The first firm offer for real estate I ever tendered in my life was way back in 2002 on a tragically rehabbed trinity just off 3rd street (it was all fine and cute except the kitchen, with low end Home Depot cabinetry hung crooked, and open holes into the crawlspace) They asked 138K, I offered 100K. The BRT website showed me they had bought within the year for well less than that, unless it was a total junker and they had spent for structural work, I personally found my offer to be entirely fair. My agent was worried that would be insulting; the next day the seller's agent said "that's insulting" and a month later (after I had a different contract working) the sellers agent came back and asked my agent if I was still in the market. So I guess it wasn't insulting so much as the market telling a deluded dude what his property was worth. Stand by your guns, you know what your offer and limits are, and it's not so much your agent wearing down the buyer in this negotiation (I don't know what you are expecting in terms of "negotiating" from your agent - you are the alpha and omega for the entire offer, and your agent gets to deal with the photocopying and the phones and correct language for you) as you having a live, 3-day-to-expiration written cash money offer ready to move and get the moneypit off their hands. You should offer them speed and no complicated contingencies if you are lowballing, but the dollar amount is entirely in your control and don't let your agent tell you otherwise.
Your agent is making 3% on the deal, if this really offends you, keep them and ramp down to 81% and move forward with your life. It can be up to the seller to ask the two agents if they're willing to take a haircut to close the deal.