A person living with their parents wouldn't bother me if I knew that they a) had no choice and were struggling yet still trying, b) had just moved back in due to financial problems or helping someone and c) did very much want their own place.
I was very turned off by one of my dates who cheerfully told me he was 40 and living at home because his mum does everything for him and why would he leave when he gets it so good? A dependent mummy's boy with no ambition, drive or self respect- no thanks.
As for no relationships that would raise a flag with me and I'd wonder why. I'd still go on a couple of dates but if I saw any other red flags such as the clinginess you mentioned then I'd run for it. For some women it wouldn't matter, some equally may not even give a try.
If you want to lose weight I recommend the 30 day shred, my sister does it and it's really helped her. IF you see it these things as obstacles then really the weight and living at home or the only ones you may be able to do something about. The past is in the past, you can't change that so just stop worrying about it as a factor.
As someone mentioned above, you need to figure out if you are unhappy and want a relationship to make things better (which isn't going to happen) or if you just want a partner. IF you are unhappy in general, you need to look at what makes you unhappy and see what, if anything can be done. If you are just ready for a partner then stop beating yourself up and worrying about who you are so much, if you don't like who you are you can try to change.
The positive things I look for in any partner is that they make me laugh, they're a good person, that i'm attracted to them and them to me and that I want to spend time with them because their personality is attractive.