Your results are good. You can dilutedilute out the salt then stop the daily water changes. But monitor the water until you go away and any day you see ammonia or nitrite, do a water change.
Your routine is a little light on water volume and frequency. Do 50% weekly. This will prevent the nitrates rising (20 is the maximum recommended and as this is your reading straight after a water change it will go higher). Weekly is great but when life happens you'll know that 10 days or a fortnight won't be a problem.
The filter maintenance is good. What is the substrate? If it is gravel it is best to vac it with every water change.
When you go away, do a water change the day you go or the day before and don't feed the fish while you are away. As long as it is only one or two weeks the fish will be fine without food, and in planted tanks there are opportunities for them to eat microorganisms. Other people tasked with feeding the fish almost always over feed and automated dispensers can malfunction dumping the whole lot in, so both are best avoided! Fish do not need regular food energy like mammals as they are cold blooded. When you get back, the fish will be healthy, the water conditions will be good and the tank will be pristine.