I think the thread's title says clearly that it's all about schematics.
A component always consists of a SYMBOL and a PACKAGE. The symbol grid is normally 0.1" (Eagle standard) while the package grid depends on the package footprint as supplied with the datasheet of the manufacturer.
Both, symbol and package are then combined to make a DEVICE, which carries all information about symbol and package and additionally the assignment of corresponding pins (from the symbol) and pads (from the package).
An ERC with hundreds of error messages related to connections has absolutely nothing to do with a PCB design - at least initially. It will have a relation to the PCB as missing connections on the schematic will not have air wires on the PCB - meaning the component is connected partly or not at all.
Don't try to sell apples for pears please.