How are the taxi drivers out there? Are they as crazy as the ones in the states?
Well, they say if the psychiatric wards are full, they start giving out taxi licenses instead

Nah, apart from such jokes, I haven't had any negative experiences so far. Some divers are nice, some are grumpy. Not all speak english, though.
Also being as cars tend to be smaller in Europe, whats the typical car type for taxis out there? Are there larger ones or vans?
There are different sizes. I think you will not have problems to find one that is big enough for all your luggage.