Fonts out of Alphabetical order

Just as BT is bitstream, PT is Paratype. This is their take on Futura, a font designed in the 1920s, which was then cast in metal for typesetting a letter at a time. So each digital Futura font is a reference and redesign going back to the original design by Paul Renner (than you Wikipedia!) They will have tried to keep the spirit of the original font so they are likely to look pretty similar. But the font metrics (widths of each letter) are likely to be different, perhaps noticeably so. This is why agreeing on an exact font is important.

So, once you have the right font and you've converted it you need to refer to the client's intention to see if the text still fits where it needs to. But since you are doing a major repurposing (brochure to presentation) that's probably ok. If you want to include exact images of the brochure, there are better ways to do that (using their stuff as a placed PDF).

I wouldn't try to imply anything malicious, fonts are a minefield. My view of Google is different: people with bad stuff on the web are often really good at gaming Google. It's much easier to end up with pirate/counterfeit goods than you might think. Google don't do any checks for legality or piracy so far as I know. Add to that, some people simply assume all fonts are free and try to make sites with the biggest collection of "free" fonts that they can - often to make money from advertising, but not always.

To answer your question: buy fonts from a reputable supplier. Such as Adobe, or a font maker like Bitstream or Linotype.

One model if you and the client are both on CC is to use only Adobe's fonts that you get with the subscription. This may change over time, but for a short duration project it's pretty safe.

Another point: many clients, printers, service providers, designers and others will tell you it is perfectly ok to share fonts for the purposes of a project. This, I'm afraid, is nothing but a convenient untruth, because the alternative is both time consuming and potentially expensive. A service provider who keeps their fonts legal may struggle to compete with one who does not.

Here’s a thought. I’ve noticed that fonts called Adobe Caslon appear under “C”. Nobody much minds but it isn’t obvious how it happens. My guess though is that the fonts are shown by the font name but ordered by the family name. But that doesn’t explain your result where your Furura fonts are mixed freely with the Gs. I wonder if the family names are made up rather randomly with Gs. Free fonts are often made By unauthorised copying by people who don’t know the full details of font design and classification.

The BT in the name stands for bitstream, a major font house. But their fonts are generally carefully made and certainly aren’t free, so your free font source is unfortunately rather suspect here.

The designer may have used a different commercial font, a different free font, or one they found in their system. ”Found on the system” fonts are often a problem for collaborating.