Five yellows results in a ban, but only up to December, after which there's an amnesty and you need ten yellows to get a ban and it's an automatic two match ban.
No. After a certain date (somewhere near the end of the calendar year) the five yellows suspension no longer applies - it's 10 yellows after that date. With reds, it depends on the offence. A professional foul or two cautions just mean a one-match suspension. (Two cautions used to mean a two-match ban, but they reduced it three or four years ago, I think.)