I say this because you are a friend and I know the workings of CCBill rather well. Any claims that CCBill turns up or down their fraud scrub or "fucks with" your revenues in any way is utterly preposterous. Since they only make money from your completed transaction and in fact loose money on each denial (its still cost them for gateway cost, etc) then is makes no scene for them to refuse qualified transactions.
Did you look at your decline rate or track your bounce rate from your tour/join pages?
If you want some assistance on how to better analyze this, give me a call or email and I'd love to assist but I think there is a probability that a bit more is going on here than just CCBill.
If you still think there are technical issues then Paul K will find it. He knows that system like the back of his hand and is very very capable.
Your load time assessment, may have more merit than you think. As we have discussed in the past, load times over 2 seconds is unacceptable by most users.
