Inconsistent line thicknesses in print preview - This is likely related to print scaling. Make sure the print scaling is set to 100% or Actual Size to see the true line thicknesses. You can adjust this in the Print dialog box.
Drawing larger than paper size - Go to Print > Page Setup and adjust the free roofing contract size to match the size of your drawing. You can also check the print scaling option here to shrink or fit the drawing on the page.
No line thicknesses when printing/exporting - Check that "Print lineweights" is enabled in the Print dialog box. Also make sure any lineweights are defined in the drawing properties. Use a thickness beyond the default 0.0030 inches for visibility.
JPG export is a black dot - Try increasing the resolution on export to at least 300 dpi. This gives more detail for the JPEG format. Make sure you are exporting the full page size rather than cropping if the black dot is in the center.
Overall, double check the print settings and drawing size vs paper size. Adjust line weights and export resolution. Let me know if you have any other questions!