OP's impetus for wanting to make this exchange (pretty ambitious task, if you ask me) was that he wanted a venue where it wouldn't be all about speed. To have a mechanism to serve as a speedbump of sorts, to level the playing field for all participants is his idea (sort of an IEX for FX).
Most ECNs don't address this issue - there are some, however, that do.
Yes, this is the key point, isn't it? Can a system be designed that levels the playing field, without introducing delay?
The only answer that I've come up with is a system designed for algorithmic trading, that equitably runs everyone's algos
directly on the server.
That invalidates the need for colocation, because everyone's algos are running locally. It doesn't matter if you're a retail trader with a dial-up connection, or a major investment bank with a colocated fiber link. Either will upload their algo, run it directly on the server, and they both have the same access speed and privileges to both market data and the order pools.
In a race condition, when two algos are fighting to buy/sell the same financial instrument, the next order to be matched is randomly selected.
"Non-display fees" actually gave me the idea. Recall when the exchanges cranked up the fees for algos so unbelievably high? Like on the NYSE, USD70/month/subscriber for a standard display, vs USD6000 per month for non-display? At first I was furious: I almost cracked my monitor with my cursing. That actually prompted me to join ET; check this post:
https://www.elitetrader.com/et/threads/non-display-fees.301156/#post-4403250
But then light bulb went on: there is a vulnerability there: algos level the playing field to the point where they must be paywalled. They don't want people writing algorithms; it's too easy for a smart developer/quant/mathematician to rake in profits.
Ritchie will do the exact opposite: encourage and support those writing algos. By the way, no "non-display fees."