In general, especially if you're running 3+ times a week, unless you're a top alien your weekly points will be pretty much the same regardless of your iRating.
iRating does a pretty good job of averaging out to a fair points haul, so long as winning the race you're in would net more points than you expect to earn on any given week. That's really the only way the system breaks, is if you run away with the win and still drop that race.
Looking at your results, iRating isn't going to hold you back. You're about 1s behind the alien pace, and 3k iRating is likely enough to keep you in the top split for the series. As long as you're running the top split, it doesn't matter if your iRating is 3k or 13k you'll score basically the same.
If you're serious about the championship, run as often as you can when the races split and only in unsplit races if you will have fewer than 4 on the week (just for some spare iRating). Race as often as you can for experience, and focus on improving your pace and consistency. Racing less or farming iRating won't help you, running Ruf Cup will.