I love the taste of peat I love Isla Whiskeys with their salty iodine seaweed & smoky flavours. I made two smoked beers the first one was just blah, to many ingredients no single style idea. My second attempt was an English Smoked Stock Ale. With 35% Simpsons peat malt, Simpson Dark Caramel Malt, Gladfield Munich, Dark Brown Sugar, Simpson Black Malt. I boiled / caramelised the first 10 litre of the wart drawn from the mash tun. It was my best beer ever, even non smoked fans enjoyed it.
Next time I will push the Peated Malt to 45%. I think the beer worked because the caramel notes played against the smoked earthy notes. The Simpson Peat is two times the PPM that of the Gladfield Peat. So you could go even higher then 35% if you use the Gladfield Peat.
If you love smoked meat, bbq, bacon & Isla Whiskeys, then the sky is the limits, if you dislike salty iodine seaweed & smoky flavours I would just skip this style.
I have drunk the Yeasty Boys 100% Simpson Peat malt beer, it was to just a little overboard. After drinking a single bottle I felt like I had just eaten a few kg's of heavy smoked red meat. Not a bad thing but not so good out of a small bottle.
I would say 30% to 60% is a good range depending on your palate.
PS. I am an ex smoker, cigars & tobacco this has skew my palate. Be warned.
Looking at your recipe I would drop the chocolate, with the smoked flavours you have enough going on.