I used to solve code golf puzzles like you, but then I took an arrow in the knee
Python, 599 chars

import os,sys
from math import*
I=os.read(0,999)
O=[]
h=v=0
for i in I:
 if'#'==i:O+=[(h,v,h+1,v+1),(h+1,v,h,v+1)]
 if'O'==i:O+=[(h,v+1,h-2,v+3)];T=(h,v+5,h-2,v+7)
 if'}'==i:e=h+.5;c=v+.5
 h+=1
 if'\n'==i:v+=1;h=0

def X(K,L):
 A,B,C=K;p=L[0];q=L[2]-p;r=L[1];s=L[3]-r;A,B,C=A*q*q,2*A*p*q+B*q-s,A*p*p+B*p+C-r;d=B*B-4*A*C
 return 0 if d&lt;0 else any(0&lt;x&lt;1 for x in[(sqrt(d)-B)/2/A,(-sqrt(d)-B)/2/A])

R=range(1,999)
for v in R:
 for z in R:
  z*=pi/999;d=v*sin(z)/10;b=-v*cos(z)/10
  K=20/d/d,b/d-40*e/d/d,c+20*e*e/d/d-b*e/d
  if X(K,T)and not any(X(K,x)for x in O):print v/2,z;sys.exit(0)
print'ERROR'


The X(K,L) routine takes a parabola K=(a,b,c) representing y=ax^2+bx+c and a line segment L=(a,b,c,d) representing the segment between (a,b) and (c,d).  Both obstacles (O) and the target (T) are repesented as line segments.  All distances are scaled by a factor of 2.

The example input gives the following trajectory (by default, the minimum velocity one):

  --                             #          --            
--                                            -       O   
                        #                      -     /|\  
                                                -   / | \ 
            #                                    -    |   
                            #                     -   |   
                                                   - / \  
                                                    -   \  


you can reverse R to get the maximum velocity path:

                                 #                        
-------------                                         O   
             -----------#                            /|\  
                        --------                    / | \ 
            #                   -------               |   
                            #          -----          |   
                                            -----    / \  
                                                 -----  \