I think you can sadly. If they think that you are taking the piss and just having days off for the hell of it say, they can and will fire you for it. My current company is terrible to their staff for reasons for being off sick.

idk I just want my foot rubs :)

Wouldn't think so

Company's do if they think u are unreliable. Its shit

Everyone has a disease in me

no

Yes if you re sick many times

If its fake yes

No if your sick just self cert yourself

It known to happen