You’ve got to love this line of work to be successful in it. If your only goal is to make money choose something else.
You’re still young and have a lot of decisions to make. I admire your ambition as far as looking to the future of your career and commend you for what you’ve accomplished so far.
If you ever get a chance to talk to one of the senior heavy line guys or driveability guys at your dealership you will find that the most experienced ones absolutely crush flat rate times, even most warranty pay jobs. As you see pattern failures and gain experience you will find that you can easily beat book times on most things. I remember Ford Taurus heater cores that paid 5 hours that I did in less than 2. Chevy Tahoe fuel pumps that booked at 2.2 and I had done in 45 minutes.
My advice on getting to that point? Specialize in something, either one make of car or one kind of work. I’m a “bumper to bumper” mechanic but it’s going to be difficult to keep it up much longer. Too many systems to learn, tools to buy, etc. The shop I run now has one alignment/brake tech, one diesel tech, one heavy line, one general service/maintenance, two driveability/electrical/HVAC, and I do a little bit of everything. And it works quite well. I know of other shops that have one Euro tech, one Honda/Acura tech, one Ford, etc. That works well too.
I should also add that except for one 4 year stint I worked 6 days a week until I was 42 years old. Work a little harder and longer than the other guys, and you’ll get ahead. But that applies to any line of work.
As for the inspections your doing, that’s the dealer’s way of drumming up profitable maintenance items. It’s a pretty good deal for the guy running the flush machines. Not so good for the customer or the guy doing the free inspections.