Welcome to the forum Brian.
Like everything else it depends on what you want and what you may or may not be willing to compromise on.
Yes, taxes may be lower, but unless your wife stays at home to look after your child you'll find any child care here is very expensive until they reach school age - by which I mean age 6/7 when they start normal school, though they go into kindergarten for a couple of years from age 4, but I think it's only a couple of mornings a week, not full time.
In Geneva proper it may not be too difficult for your wife to find work, but again it will depend on her level of training/experience. Try these websites to see what may be available: www.jobs.ch www.jobup.ch www.monster.co.uk
(change the location setting to Switzerland - it can be done, but sometimes it's stubborn about offering you the choice)
Kids coming home from school can be a surprise, but remember that often parents come home for lunch too. More schools are beginning to change over to lunch at the school, but it'll really depend on where you're living as you won't have a choice in the same way as you do in the UK. Your child will go to the nearest school to where you're living unless you want to put her in an International school.
Geneva proper can be a nightmare traffic wise even with public transport so you might want to think about living outside of the city somewhere in canton Vaud or even across the border in France and commute from there.
Yes Switzerland does have a very direct democracy, but don't expect to take part in it. Foreigners are not allowed to vote here, except in a few cantons and only for things like electing your local commune (town) councillors. Even then you have to have lived in that particular canton/commune for 5 years and have a B permit before you could vote. http://www.ekm.admin.ch/ekm/fr/home/...timmrecht.html
I suggest you get hold of a copy of "Living and Working in Switzerland" by David Hampshire. It's full of useful info for both before and after you move here. You can order it from your local bookshop and also via the Internet. Also have a read of the various sticky threads at the top of each section of the forum, they'll give you a lot of information too.
I'd also suggest that, if you haven't been to Switzerland before, you make a trip here to get a feel for the place and to see if you'd actually like it. Switzerland is a land of rules and regulations which may not suit you as much as you think.