Please remember that if you are investigated, the tax agency may well talk to your neighbors. They may even wish to talk to your customers. Using a fictitious small business to launder money is not a new idea and they look for it. In fact, they have good data as to what every different category of small business should be pulling in, for both revenue and profit.
As for deposits, it is at the discretion of the teller as to what reporting, if any, is done up to $10k. As several persons have noted, that may have been "unofficially" lowered to $5k. In any case, if you look suspicious to them and deposit $1k cash, they may well file a report. Whether the tax agency has the resources to follow up on such reports, that is a good question. The general rule is that they won't waste time on it unless they expect to recover in excess of what it will cost them to make the effort.