It's all good and well saying that being faster is more important but if you are not consistent, in race conditions any time you gain from those few good laps will be lost buy the many mistakes/offs you're likely to have when you try to drive too far beyond yourself.
Perhaps, but if you aren't fast then /all/ your laps will lose time.
Besides, consistency of time doesn't necessarily imply or require consistency of action (or in other words, there are billions and billions and billions of different ways to drive, say, 1:47 at Brands in the mini. So much so that it's a bit of fallacy to imply that changing what you do will make you slower or that if you get 1:47 twice that they were the same lap...that's probably the telemetry's best use over simply driving laps and comparing the times)
Besides, any lap time that is less than the optimal, unless it's because of traffic or so on, already has lots of the mistakes you mention in it, by definition. All the consistency stuff really boils down to is something like " it's important to keep making the same mistakes over and over again "
In a race I'd argue that you'd probably expect to be less consistent and to rely far more on driving for the conditions of the moment, because of traffic and because there's more to finishing a race than doing x identical laps.
Being consistently slow is a waste of time. You'd be better trying to get those few fast laps, and at least gaining some time and maybe learning something in the process too, other than what to do when you see a blue flag
But I'd argue that consistency is something you get for free anyway. If anything it's the converse, we are creatures of habit aren't we? It's breaking the habits that will (hopefully) let us improve our laps.
Speed. That's the hard one. Focus on that, and you'll be consistent by the time you are fast.
What is more important is to be able to analyse and deconstruct your laps through replay or telemetry data or even gut feelling to see when and where that time was gained and therefore unlock the key to a faster lap.
Well, the big piece that's missing for most beginners is that we don't know what is fast in the first place. What it looks like. What it feels like. What we should be trying to do.
The target most have is the lap time (this is what tells them) but we really need different targets.
Being fast isn't the only thing that matters, but imo it is the only thing that's difficult to do and the thing that requires the most skill and effort to obtain.
What is fast eludes me. But I can say without any doubt, if you do the same thing this lap as you did the last one, and the one before that then you won't get any quicker.
Indeed you'll probably find it difficult enough to be quicker if you don't do the same thing, without needing to train yourself to be slow every lap