1. A much bigger issue is NTSC composite. Making it look like a CRT is a much smaller part of the picture than what NTSC composite effects do. For example, If you were to hook up the RGB headers on an SNES (yes, the SNES has RGB headers on the board) to an actual CRT it would look awful because SNES games were designed with NTSC blending effects in mind.

2. There are scanlines and there are good scanlines. Most artificial scanlines look like garbage and not at all like an actual CRT's scanlines. There are some good filters out there, but you really have to do your research. If you see the words "slot mask" used to describe the filter, it's probably good. This is one of the reasons I'm a fan of the CRT-Royale reshade filter, because it does an excellent job at emulating the look of a slot mask.