There is actually only a couple of SA's in the Aus operation the company has been bought and sold a couple of times since it was SA owned.
As for the questions; Not specifically Execujet but if you are looking at corporate this might help.
Roster patterns, Depends on the client but most corporate gigs in Australia at least don't have a strict roster. Some people like it some people don't it's not for everyone.
time away, Really depends on the client or owner of the aircraft. Anywhere from day trips to a month away maybe even more. usually larger companies or more mature owners understand the work life balance.
days off, you can some times get weeks off at a time and then you can be flying every day.
destinations, Again depends on the owner of the jet or charter operation, it can be anywhere in the world or 30 min down the road each week.
Salary, you guessed it depends on the client, it really varies from company to company from owner to owner.
As you can see there is not allot of uniformity to any corporate roll but it really is up to the individual to know if the industry is for them.