To further quote you, bitshares bitGBP are awesome for us people in crypto world. Now please try explaining those to your small business owner? How will you introduce and pitch this system as being nore simple than corporate payment processors?
Whatever questions you have for me about this are also questions for you to answer about your own currency. Don't waste your time reinventing the wheel here. You could apply the wasted time and effort (and cost) of creating a new cryptocurrency to the merchant adoption phase with bitGBP.
edit: in fact, I can even help you with the adoption part, since I'm running an open source bridge from BTC into bitBTC - I can provide you with half of what you need to implement a GBP->bitGBP bridge completely for free.