If possible you should interface your cash register and credit card payments. Interfacing can make you more money by eliminating errors and re-keying errors while making transaction fraud near impossible protecting you the business owner and your customers.
Don't store money in a cash register while you are closed. Remove the cash and store it in a safe or get it deposited. If a thief were to break in to your establishment and noticed the cash drawer register is closed the next thing that will occur is the cash register will be stolen or destroyed. We replace cash registers quite often due to it being kept closed during closed hours. Leaving an empty cash drawer open may even deter a thief from breaking in should they be able to see from a window the drawer is empty.
Also keep paper in your register even if you do not want a receipt or journal. If your register has a two station printer you really should keep paper in both sides even if you don't really want the tape. The problem is worst in cash registers with dot matrix printers. The printer attempts to print rather or not there is paper in the printer. Without paper the printer will strike the ribbon against the platen inside the printer. Too often the platen will become swollen with ink that should have been printed on the paper. As the platen swells it will become lodged in the printer and may even ruin the printer. If you don't want a receipt or journal but you machine has them then open the manual and see if you can turn one off, or limit what is printed.
What is the best printer type? I prefer thermal paper printers when possible. Thermal printers are fast and quiet and rarely require service and help reduce downtime. However keep in mind if you need to validate a guest check or invoice then you won't be able to use a cash register with a thermal printer.
What is less expensive to operate a cash register with a Thermal Printer or Bond Paper printer. I believe although I have no hard numbers to back up my theory the thermal printers are less expensive to operate. Thermal printers do not require a ink ribbon. Thermal rolls often have far more paper per roll then the heavy bond paper rolls. Lastly I think in the coming years we will see thermal printers last much longer then the older impact printers saving you money in repairs and replacements.