I can't comment on how much cash they do or do not have. Considering a purchase of a 250-unit apartment complex in Fishkill, NY for an undisclosed amount, but a transfer tax of $57 million, this puts it at $228,000 per unit. They'd have to have SOME cash for this sort of transaction.
As for baptisms, I'd be willing to wager that the majority are children of JWs. Our recent Circuit Assembly had three baptized, all under 18.
As for the increases in number of congregations, it appears to be foreign language "groups" being formed into actual congregations. One of the speakers at the CA mentioned three new congregations formed in the U.S. from Russian-speaking groups. Based on the number of baptisms, there are less than 3 new publishers per existing congregation, so that wouldn't normally warrant new congregations being formed. However, foreign language groups morphing into congregations would, as would the formation of english groups in non-english countries. This seems to also be on the upswing.
Is there a decline? No. Slowing growth? It would appear so.