ìI don't want to change my normal routine for a single purchase.
I haven't asked you to "change your routine". I asked you if the site works by clicking the "Buy on Web" button of our site from a normal browser *outside* FSX, AS A TEST, trying to understand if your PC cannot reach the Esellerate site globally, or if you cannot reach it JUST under FSX, because it's the *FSX* app that is being prevented by opening the site from itself, which would indicate a block of *just* the FSX app.
Quick question - if I buy directly from FSDT web-site, will this order be linked to my FSDT ID (meaning e-mail)
There's no such thing as an FSDT ID or FSDT account for purchases. The only account you have, is the forum account, which is not linked to the purchase process.
Every order you made, it's linked to the email address you decide to use for that order, so you might want to always use the same one for convenience, because it will be easier to retrieve the orders in the future if you lost them AND if there's a Coupon or an upgrade offer, which is usually related to the email used for a past purchase, it's best if the email you use it's always the same, but every order is separate, they are not really linked to an online account.
It might look like an account, but that's just because, in the integrated purchase process (only), your data is saved locally (in the registry), so you won't have to type it again for future purchase, but it's something entirely local to your system.