I can only really reply to the viewfinder question so I will stick to that.
Whether you can adapt to not havng an optical viewfinder depends on your personal taste but let me tell you what I have found with my Fuji P&S (31fd). I need reading glasses now, and so using the LCD is a big pain for me. Aside from bright sunlight viewing issues, I can't properly see the LCD without glasses to begin with. When casually walking around, I don't want my reading glasses around my neck. So, the framing of shots is guess work, to some extent. Back home on the computer, I often discover details in pictures that I was unaware of when taking the picture. Also, I have lots of non-horizontal horizons. In some sense, for me, using a LCD viewfinder p&s is a lot like shooting with film. I don't know what I really have until I "develop" the picture.
I have owned a P&S with an optical viewfinder (Canon G3). The usual complaint with these is that they do not show 100% of the scene and that you can get parallax errors depending on subject distance. I find that the more I use a camera the better I can compensate for these, but I can't compensate for not being able to see the rear LCD.
Having said all that, for casual use I can live with the LCD framing. I lose the odd picture, but so what. I would not give up the chance to have a wider angle lens just because there was no optical viewfinder, for instance.
In the past week, my 31fd has developed an extreme banding problem and I think it's dieing. I am tempted by the wider angle LX3 and the Sony W170 (wider and optical finder but no diopter adjustment) but may end up with a Fuji 40fd just because it's cheaper and because I already have the right type of memory card for it. From what I can tell, these things aren't designed to last very long so even if you buy something you don't really like, it may not matter much because you'll end up buying another in a year or two regardless.