There is no penalty for failing several times because only the last retake scores are recorded in transcripts.
As a university professor I am currently fighting to include not just the final retake score, but also previous scores, on transcripts so that diligent, hard working students are rewarded and graduate schools/employers have more information about whom they are hiring. I respect a student who retakes a hard course to get a better grade; I don't respect a lazy student who needs multiple retakes because they aren't studying and their transcript shouldn't conceal this behavior.
Yes, but ultimately, what matters most is how well a student has mastered the material.
One grading extreme is here in the States. For example, my two youngest kids take two spelling tests every week: a post-test on last week's material, and pre-test on next week's material. They have no idea what's on the pre-test, yet their pre- and post-test scores count equally toward their overall grades. It seems unfair to grade someone on material that hasn't been covered, but I can't change this. Some teachers at my eldest son's middle school use this approach, too.
Umm...you seem to have a bit of an axe to grind on some of your students. Do you have evidence that everyone needing multiple retakes is being lazy? What if they had pneumonia or a family member got cancer or whatever?
How do you distinguish between students who retake a hard course for a better grade due to laziness vs. those with, umm, noble motives? Plus, some less-arduous students become great employees; why do you seem to be trying to find a way to block them from even getting out of the starting gate? Let their employers worry about how they do on the job.
Just my two cents.
Val