For the small tabs, you may try to enable custom stylesheet (userChrome), there are plenty of themes on the web, but if you’re looking for something more specific you may edit it yourself, it’s very easy. Oh and the default start page is pretty ugly I agree, there are plenty of alternative start pages on the add-on store For the data collection, firefox forks like librewolf should have that disabled by default (I don’t have any experience tho)

What may this cause to a casual fedora user?

some people enjoys it, some people doesn’t. from wikipedia:

Spamming is the use of messaging systems to send multiple unsolicited messages (spam) to large numbers of recipients for the purpose of commercial advertising, for the purpose of non-commercial proselytizing, for any prohibited purpose (especially the fraudulent purpose of phishing), or simply repeatedly sending the same message to the same user.

the keyword is unsolicited: you don’t want it? just don’t add it to your communities. you want it? add it to your community. it doesn’t bother you at all if it’s unsolicited.

so you are able to not subscribe to it or even block it if you want

because most bots are spam doesn’t mean that all bots are spam. unrequested invasive bots are definitely spam, but bots that can be enabled or disabled freely do nothing wrong IMO

I absolutely agree, that’s why I made it togglable by anyone who likes