Ixamyakxim: I've always been a bit curious about Firefox but I don't like installing "third party" stuff and a lot of people always mention scripts and such in the same breath as Firefox. Do I worry too much about this? Is the Firefox package I'd download more than enough on its own and do people just run scripts as a convenience for certain features they want?
FF is a lot more secure than IE. Most of the time. Scripts? You can install a myriad of addons in both Chrome and FF. Some enhance security and privacy by blocking certain things like ads, facebook buttons and even javascript, or enforcing SSL connections, some are just convenience features, like an integrated dictionary or the ability to download all images from a site. Some are bullshit.
I recommend AdBlock Plus or AdBlock Edge for blocking Ads which not only declutters websites but also enhances security a lot, since it has happened that adservers served malicious content.
And for preventing tracking I would use Ghostery.
If you're really paranoid you can use NoScript which per default disables all JavaScript. But since pages like GOG need JS, you have to manually whitelist them - might be too much for a not so tech-savvy person.
Ixamyakxim: Installing in X86 directory - yes or no?
Yes. It's a 32bit program.