This forum is a community of racing fans with a common interest in the Le Mans 24 Hours. We exchange information and ideas and help each other out with tickets we don't need (at cost or as a swap). Some members, like Termietermite, Werner and Gilles before he moved to Dijon, do an enormous amount of work in providing really useful information. The site provides the infrastructure which makes that exchange of information possible.
I really have no idea how the forum could be adapted to fund the forum, as any payment for registration, or posting would just be a discouragement. In fact, if you look at posting over the last couple of months there wouldn't be much of it if it had to be paid for- the meetings at Sebring and elsewhere would be arranged by email, pure information provided by Termie and others would have to be found on the ACO site or other forums, and the jokes and trivia would dry up.
I know that there's more to CA than the forum, but that's not somewhere I ever look, and I'm not at all sure that it can provide a service which a large volume of fans will pay for.
Merchandise can be tricky in that it involves holding stock which may or may not sell - me I'd pay not to wear a Le Mans Teeshirt or own a Le Mans mug of any description, but that's personal taste. As at last night Delboy had orders for 86 teeshirts and 9 mugs, how many would CA have to sell, and at what price, for a decent profit to result?
Charity is a separate issue, but lots of us have a charity budget for our favourite charity/ies, and then make impulse donations to charities which grab our attention through the year.