I don't see how my idea would actually allow these syndicates to cheat any more effectively than they could if they use the TL.
Lets walk through a scenario.
I, being me, one person - start up 10 new teams on 10 different computers that I have access to at various locations, different IP's and different email addresses.
My new teams all start with a bunch of rookies, and generally, you start with at least one good rookie. 18 or 19 Superstar potential at least.
I trade amongst the 10 teams until all the good rookies are on one team - this will be my main team. I don't trade directly from the 9 teams to one parent team, i perform multi-stepped trades such that a player goes from team A, to team B, to Team C, then to Team Alpha (main team).
Because i can trade and accept trades straight away, i can perform all these actions in a few hours. None of the trade restrictions will prevent me from trading young players because their salary and skill sets will all be similar, and even then, I can trade slightly less-potential players for better potential players and no one will blink an eye (who cares about a $3k salary 18 year old Per-allstar being traded for an 18 year old $3k salary all-star potential.).
So I now have my main team with all the good rookies on it. I don't log All 18/19 year old superstars or better potential. i start listing them one at a time on the transfer market for $300k each, and bam. in one week or so, I now have $2m in the bank.
Cheating....
THIS is why trading will never be allowed in BB. And unfortunately, there is no restriction, or method that can be put in place, which can monitor trades effectively to stop trades. There IS however mechanisms in place which can stop and monitor transfers. Its not perfect, but it helps.