Yeah, actually none of them are real friends, everyone is acquaintances made throughout the careers. I tend to befriend people who play an interesting tactic or who have nice looking teams in Cup or Champions League. If they abuse the Friendly-option I get rid of them real quick though.
Well that's a conspiracy theory if I ever heard one!

It might well be, I'm finally in a league where at least 6-8 teams seem to be active so everyone is watching the games of their rivals or supporting those who they've followed for some time. It's an added level to the game imho, but it wouldn't surprise me if Nordeus had certain 'failsafes' installed.
Kind of like how it always seems as if you stock up on reds you immediately get a bunch of injuries so you have to use them up. Might just be coincidence though, I've had rough patches on the team I run semi-actively on my phone as well where it seems the whole team goes injured for lengthy periods of time and I don't do any farming or buying at all there..