Have a look at my website (click the globe symbol under my username).
The bow on the homepage is 75# at 28" and 90# at 31.5" self Yew (as are all my longbows).
Warbow is a loose term and I'd suggest something similar the one mentioned above is a good start, of course you may want to get just over 100 for the heck of it.
i'd say 100-120 is a reasoanble weight (at a medieval style 30 plus inch draw). I saw someone pulling 170 a few weeks back
, but that was an exceptional spliced billet Oregon Yew bow.
No no no no no, don't back a Yew bow unles the sapwood is compromised or has been removed. You may however need to reduce the sapwood thickness to about 3/16 - 1/4" to avoid having too much sapwood at the tips.
Regarding dimensions, I'll throw in some figures for the bow obove later on, but be aware the dimensions very much depend on the quality of the wood (also the length, and the bow above is fairly short).
Del