Most traditional bows are woefully inaccurate, but you can achieve some degree of consistency with a lot of practice and good technique.
A bow is a bow at the end of the day and its all about the archer. Unless you start sticking sights, release aids, stabilisers on the thing then they are essentially the same.
So far as speed goes there is also very little difference if any between the two. It was only recently that glass bows started to hit the 200fps mark and a very well designed bow can reach 190fps so nawt in it.
Longbows and horse bows have a V E R Y steep increase in draw weight towards the end of their draw cycle, so yeh start light and build your strength up.
No well designed bow should show a drastic increase in draw weight towards the end of the draw unless it is poorly designed. A sharp increase towards the end of the draw is called "stacking" this means there is a problem with the design be it string angle or tiller. This can be seen in a bows FD curve (force draw)