The year-long season appears to be on the cards, too - but the AFA is still very, very poorly run. And I agree with Palestrino, it seems to happen in all of SA federations.
However, I disagree with you on the relegation system. Recently promoted teams, even if they achieve a mid table finish, which would be a good achievement in pretty much any league (Bar ours - oh, and the bolivian league...), get relegated. The average system was introduced when 'big' teams were in danger of being relegated, because, since they had had good seasons in the past, their sorry ***** would be saved. And this is what happens in practice, basically:
Let's suppose Instituto get promoted next year and Boca are champions this year. Next season Instituto gets relegated after achieving a midtable finish, while boca have a **** season, end up last, but their better average record saves them from relegation. Now - a bad season would lower said record, right? But, as they're a big team, they fill their stadium consistently, get the best sponsorship deals, and attract the most promising youngsters, something smaller teams can't do (Which is not saying they don't have youth products of their own, even we do!). That gives them a 3 year margin to save their *****, while having all of those advantages.
The only thing that endangers larger, more established clubs is financial mismanagement - During the Aguilar era, corruption was rampant in River and you can see it now - they've barely signed anyone. The team isn't getting paid since the summer. Same with Independiente (Regarding wages), players haven't been paid in 3 months, and they didn't get the cup bonuses from last year.