Could we have some commissioners with commercial experience please...
This looks confused. Some of the principles sound OK - a car rental company should not be charging different prices for consumers from different countries. But the details are all over the place and there's a huge potential for confusion with existing local laws and regulations - for instance some countries don't allow food to be shipped across borders, some require qualifications to offer certain types of products or services; certain types of promotions or marketing is limited.
It also seems to flip-flop. In one part a trader cannot be forced to contract, in another it says the website has to be available and a third says if he is 'pursuing activities' (which is a website?) he's not allowed to differentiate or refuse to sell by virtue of nationality or place of residence - which reads like if you have a website, you'll be forced to contract. And that opens up a minefield of legal risks including fines for breaking rules you've never heard of written in languages you do not speak.
In theory, you can offer to supply just in your country (the customer collects), but some people will be selling by drop-shipping, so have no physical premises from which they sell goods. And some will have exclusive distribution agreements or licenses for specific territories or areas. This might include service contracts such as on-site service that only apply to a given territory, dealer training etc. It's not at all clear how these would be dealt with.
And even with all this in place, you'll still get a Spaniard living in London trying to buy a present on her Spanish credit card for a nephew in German to be shipped by an Austrian supplier that will be refused because the risk of fraud is much too high, and there is no clear legal recourse for the trader. So it may very well act as another reason not to trade online - just like the EU VAT laws.