If you had your ideal Bitcoin to Currency Exchange, and of course Currency to Bitcoin, what Kind of features would you like?
Here are some basics I suggest.
A 24/7 Market
The ability to load Any currency into it (usd, euro, w/e)
The ability to view current charts
The ability to place buy and sell limit and market orders
Live Charts
What else would you like in features?
And for security
A secure site in general, well and professionally encrypted
A password that must be 12 characters long
A site key, system, that makes you answer a security question when logging in from a new pc or ip address
Email confirmations for all trades, and for all stop limit orders placed
A "circuit breaker" system much like the stock market, where the market is automatically closed when it dips more than 25% in as short period of time
Anything else in the need or ways for security? And would you feel likely to use a site and exchange like that?
The company responsible must adhere to a recognised security standard which is relevant to the business being conducted and be compliant - this will cover a host of security issues too many to list in one post but for a rough idea read the following
https://www.pcisecuritystandards.org/documents/pci_dss_v2.pdf ( I am not responsible for any content hosted by that site be careful as it is out side of these forums).
The company must conduct regular compliance audits via a third party.
The company must conduct regular PEN testing.
The company must conduct regular vulnerability assessments via third party and in house.
The company must vet all employees for any convictions for fraud.
I could make a huge list since I have had first hand experience of what is involved in terms of security for a company working with sensitive data but I'm not going to since it would probably bore people to death
.