Ajax1983: Is it safe to use the platform?
It depends on what you mean by "safe."
If you mean "100% safe," then I believe the answer to that is no, it isn't, because AFAIK, the technical problems with the vulnerability in Galaxy that you are asking about has not been fixed.
However, GOG is an extremely niche, tiny store, with a very small userbase. Therefore, the chances of a hacker taking the time and energy to publish a virus that they would need to have written specifically to take advantage of this vulnerability is extremely low, since they'd need to distribute their hacks on sites that chances are no GOG user would ever happen to visit, given that there are so few GOG users, relatively speaking.
The hackers would know that, and hence they probably wouldn't bother putting in the effort to write such a virus which would most likely never give them any return on their time & energy investment.
So, the point of all that being, even though Galaxy is not technically 100% safe, in practical real-life terms, you'd probably be fine and never receive any viruses that were caused by your usage of Galaxy.
But if you want
100% definite safety, then you'd have to avoid using Galaxy.