Make it at least 2" longer than you think, much easier to loose 2" than to add it.
For 32" draw go for at least 76"
Yes you can get away with 70" if you like set and /or chrysals
Leave the tips wide early on to help counter twist/alignment issues.
Go for a wide belly, only round it slightly, basically just remove the corners, and probably heat treat the belly. all that will help avoid chrysals.
80-90# is a nice sensible weight and should be easily achievable.
Tillering a warbow has a different feel to a lower weight bow, you need to be apply full draw weight on the long string from the start. And only use a long string that is just long enough to slip onto the bow. Once 80# on the long sting gets the tips back 6" get the short string on it to say a 5" brace. You will find that 80# now pulls it back a surprisingly long way! But apply the braced 80# slowly as it is a much higher stress on the bow and the tiller may have shifted.
Del
Plenty of Yew ELB and warbow tillering on my blog (Google Bowyers Diary) it's mostlyl self Yew but there is one Hickory backed Yew and an ELM and Ash (Ash one was a real pig).