Life aboard a 24'''' sloop?
You are right you really don''t really need that much room to liveaboard on your own. But the previous post is right - we can convince ourselves of anything - experiencing the real thing is the ultimate test.
I found you can do what you want in a 26 footer although to be fair I had to change things around a bit to make it more user friendly as I wanted it. Usually the manfacturers put in far too many berths and as long as you have standing room in the galley and where you pull up your britches after using the heads then you can be really comforable in a 26 footer. Don''t expect to use to entertain all your friends at once though. That just can''t happen.
A 26 footer is comfortable for one, cosy for two (who know one another), cramped for three and crazy for four.
Your boat will be great for coastal sailing too and you will have no difficulty managing her on your own either. Costs are proportional to length so that is going in your favour too.
I''ve had larger boats and I''m now back to something more modest and in true minimalist fashion. I am not suggesting that you will enjoy it for the same reasons but certainly 26 feet is big enough.
There is some good discussion about living onboard on Tom Macnaughten''s site too. Read it before you make the plunge.