A: Technically yes, but with caution. Most free sheets carry a disclaimer: "For educational use only." If you use one for a bridge or high-rise, you must validate it against licensed software and seal it with your professional stamp.
They offer a "RC Beam Design Spreadsheet" based on ACI 318-14. It includes beam, slab, and column modules. The download is immediate and requires no registration. Reinforced Concrete Design Spreadsheet Excel Free
A: Combine Excel spreadsheets (for elements) with a free 2D frame analysis tool (like Ftool or RISA-2D Trial) for load distribution. A: Technically yes, but with caution