I had a grapefruit sized dermoid cyst removed 2 years ago. I also had the ovary and the Fallopian tube removed as they were damaged.
I was in hospital for 2 nights, although my surgeon said I could go home after 1, I still felt very sore and wanted support with pain relief.
I had 4 weeks off work - I'm a nursery teacher and wanted to ensure that I was completely well and able to cope with 30 very small children before I returned. You may well be ready to back after 2 weeks.
My tummy was very, very uncomfortable, bloated and bruised for a good 2 weeks. for the first week I did very, very little and then gradually increased my activity level.
I was a singer in a former life and although I didn't try singing straight away, I think I would have been ok after about 3 weeks, but it depends on what sort of singer you are and how involved all your muscles are (if you see what I mean).
In terms of imtimacy - it really is a "whenever you feel ready" sort of thing. I wouldn't have wanted anything particularly strenuous for a couple of weeks, but if you're not talking about full sex, then it really is just as soon as you feel comfortable.
Running/horse riding/yoga - presumably you will have a follow up appointment, so I think I would wait until after that as all those activities are high impact.
Parties - I was exhausted for the first week, as a result of the general anaesthetic I think.
For the first couple of weeks I wore very lose clothing, particularly around my tummy as I was very bloated.