Again, this is an article about German startups. But you claim that this also applies to established mid-sized (usually family-owned) companies that are the opposite of startups: They have successfully saturated the demand for the niche that they are specialized in and neither potential nor interest in expanding further (within their niche, at least). So far, you have provided no justification for your claim, besides ”surely, no one would refuse a lot of money“.

That does not sound plausible to me. Typically, your own computer would be behind a router that is either doing NAT or has a firewall (probably the former). Any incoming traffic would be directed to the router without any chance of reaching your computer. Whatever you saw was either outgoing traffic or incoming traffic in response to connections initiated by your own computer.

Connection attempts from the FBI? Could you specify that a bit further?

i.redd.it and v.redd.it might make sense as well. There is a bunch of subdomains and other domains (…oauth.reddit.com, …redditmedia.com, …), but they are only used if you connect the the main sites (i. e., not hot-linked), so blocking those will be sufficient to block all reddit-traffic.