I think this is a great example of a newbie(in LLM) who reads the rules has a question and asks it. It is these things I find to be of great benefit to this forum, however, I find the "it's your game so you can play it anyway you please" argument a tad dismissive, and I mean no offense to you jraldous, but I fear that we sometimes dismiss a perhaps promising LLM'er with these kinds of arguments.
As far as I can see this is a welcome discussion of a topic that has not been discussed in detail and to which we had better be prepared come CM4. I have only tried one online game following the LLM ethos. It was Craig, Jeff and myself who played. That meant that trust wasn't an issue, cause we had no reason not to trust each other. In LLM games trust will be the decising factor because as iajafer stated you can't tell if anyone are using third party helpers. I know who I would trust to play an online game with and who I wouldn't.
As for the loans from other human players you'd have to ask yourself is this loan realistic, if it is I say go right ahead, but I doubt many players on a premiership side would willingly go to the conference, same goes for first division, however, that said there will always be exceptions.
In the end, and this goes for all areas of your LLM game, you have to ask yourself whether this would happen in real life or not, if you find that it would be unlikely to occur, then I suggest you refrain from doing so.
Anyways, good luck with your game and I do hope tou stick around