Me Too, I think 'European super league' is a bit of a stretch. Like I sad in earlier comments, I'm not too sure of the exact mechanism with the bottom six but it wouldn't be too hard to find one that works. Maybe wins in those last five rounds boost a team's weighting in an American-style draft lottery. Maybe the bottom team starts the final five rounds with 6 points already on the board, and second-last with 4 points, third-last with 2 points.
It wouldn't be too hard to find a balance between killing tanking and being fair to struggling sides.
QConners, the bottom six would likely be linked to draft placings, in that wins in the last five rounds would be rewarded by a better shot at the top draft pick, which would ensure they would hold a fair bit of interest relative to current late-season games among bottom sides.
Sheek, one aspect to be discussion as mentioned is what happens to points earned in the first 17 rounds. Do they carry over or is it a clean slate? If it's a clean slate, does the team finishing first get say a 6-point start, 2 gets 4 points and 3 gets 2 points, as reward for their performances to that point? I like that last suggestion, as a general rule.
The problem with a rotating conference system is while it's great for fairness, it takes away more blockbusters than it provides and may even have a negative effect on fairness for some teams (given the league currently can artificially ensure top teams play more games against other top teams and so forth).