To put it simply, "targeting" the EU market means that a product is openly made available for purchase by residents of any single country in the EU by someone outside the EU.
There are three main types of market entities, or "economic operators," that engage in the production, distribution, and sale of products. The lines of each and definitions may differ from your understanding, but these were set up to at least have decent definitions for this regulation.
All vintage/second-hand items that haven't been listed for sale to the EU prior to Dec. 13th, 2024 are be subject to the GPSR unless they are antique, art (designed to be art pieces, so nothing that "doubles" as art), and collectibles (rare and with historical and/or scientific value).
This depends on the situation, but, in general, this item will need to follow the GPSR in order for you to send it to the EU.
All vintage/second-hand items that haven't been listed for sale to the EU prior to Dec. 13th, 2024 are subject to the General Product Safety Regulation.
Yes, you almost certainly do. As the GPSR is written, it's more so the products that are regulated, not the individual. What matters most is whether or not the product was "targeted" to residents of the EU.
Yes. While it is not explicitly stated in the text of the GPSR whether or not digital downloads are under the purview of the GPSR