there is definitely nothing wrong with going carb. there are plenty of them that run perfectly on the street.
as far as the guages. they are hooked up different than most cars that use them when they do a swap. look up a wiring digram for a focus's gauges. they all run directly to the ecu and you would have to figure out a way to copy that signal to get them to work. i have seen one focus that used the stock gauges and they spent a lot of time with the electronics to get that to work.
here is what they had to say about it.