Well after 20+ years of playing this game seeing the ranger go through many variations being the most changed class period, this is my take....
*d8 HD is fine (used to get 2d8 at first level, that could be an option)
*Favoured Enemy is set properly for how it improves (+1 damage/5 levels) but IMO they should get to chose a favoured enemy every 3 levels.
*I love the favoured terrain idea mentioned, limit it to one choosing out of the basic enviorments (Forest, desert, urban, swamp, mountain, artic, grassland/plains and aquatic). Make it follow the same progression as the favoured enemy granting the bonus to AB, skills and saves.
*I have never been a fan of hide in plain sight for any class other than the SD(a prestiege class in any event) so IMO it goes.
*Grant a limited d6 sneak attack starting at level 4 and improving every 4 levels there after.
*Wouldn't change their spells at all, they are the most limited spell casters for a reason and the spells they have are for minor aid only.
*I like what was done in the 3.5 as far as their weapon style choices.
That's my take, enjoy heh
Thanks
Finny