Would this idea for a crypto currency exchange work?

Hello everyone,

an idea has ripened in my head and I would like it to have opinions on it.

How did it come about: I own & run a small software company, and have several years experience in doing high-frequency trading and leading software development for automated trading. I figured the crypto currency markets are an interesting marketplace and wanted to apply my expertise. What I found was that all exchanges I could find have fees that make it practically impossible to use trading algorithms of the kind I would like to use, and some are too slow to allow for high frequency trading.

So, I keep thinking: why don't I (i.e. me, my employees, quite possibly also other interested developers) implement a new marketplace with the following features:
a) low fees - I am guessing that somewhere in between 0.05% and 0.1% per trade should be sufficient to cover costs. Alternatively: no fee per trade, but a certain percentage charged per time per amount held, i.e.: if you have on average 100 BTC in your exchange account for 1 week, you pay x% for that, regardless of number of trades
b) near zero execution times - crypto funds to be held in exchange-owned addresses, thus extremely few confirmations need to be waited for before funds can be used in other transactions
c) server-side trade scripting - provide an way to execute trading scripts on our server 24/7
d) no handling of real money - only trade crypto currency pairs (I still have to check, but this may be a result of legal restrictions)
e) serious security - enterprise-style infrastructure and software architecture
f) closed source - I know that crypto currency folks embrace open source, but I feel that copies should be discouraged where exchanges are concerned, and not making infrastructure and internal code public is an added safety mechanism - albeit not a very strong one.

How do you feel about this? Is there a need for another exchange or are there enough about already? What other features would you like to see?

Thank you for any feedback!