Sorry Ivan. VFR instructors do teach up to the CPL skill test. IFR instructors teach single engine to PT4 and if multi, PT5.
The salary is based around Oxfords famous 'bonus'. If you work hours in excess of the guidlines in the OATs ops manual than you can earn as much as the instructors were paid as a flat rate salary 3 years ago. It is possible to earn good cash, but it isn't really safe flying at that tempo for prolonged operations - note the airprox rate.
The earnings assume of course that you are allocated students, and not ones on full time ground school, and then that you can get your hands on an aircraft.
OATS is returning slowly to some of the ways things were a few years ago - standerds flight reinstituted, building layout returning to suit new 'team' structure for instructors. Of course they won't admit that. The late lamented course managers became unworkable Senior Flying Instructors (too many students) and now are changing into Team Leaders, ie course managers. Are you familiar with Petronius Arbiter, the Roman governer of Bithynia Pontus in AD65?