Euclidean Vectors

Python 2, 238.5 (594 562 482 477-50%) bytes

from math import*
def F(x):s='%.3g'%x;return[[s+'.',s]['.'in s].ljust(4,'0'),s][x>99]
I=input()
V=I.split('\n');N=len(V)
l=max(len(x)for x in V)
q=[' '*(l+2)];V=q+[' '+x.ljust(l+1)for x in V]+q
for k in range(N*l):
 i,j=k/l,k%l;c=V[i+1][j+1]
 if c in'<>^v'and['|'not in zip(*V)[j+1][i:i+3],'-'not in V[i+1][j:j+3]][c>'?']:a,b=i,j
 if c=='x':A,B=i,j
Y=A-a;X=b-B;a=atan2(Y,X)/pi*180%360
print[F(hypot(X,Y))+' units @ '+F(a)+' degrees '+' NS'[cmp(Y,0)]+' EW'[cmp(X,0)],''][I=='x']

Explanation

Finds the start and end positions by looking at each character in the input.

Start is x

End is found by looking at each arrow (<>^v), and their neighbors. If neighbors are continuing vectors, ignore. Else, this is the end.

Look at the neighbors perpendicular to the arrow direction.

If they contain a perpendicular line, then it is a continuing vector.

Examples (_ indicates space):

_#_   
->_   Neighbors marked by #
_#_ 

___   
->_   (end)
___   

_|_   
->_   (not end)
___ 

___   
->|   (end)
___ 

---   
->_   (end)
___ 

Because the end point is found, there can be any number of vectors (30% bonus).

JavaScript (ES6), 305 bytes - 50% bonus = 152.5 score

v=>(l=v.search`
`+1,s=v.search`x`,u=0,d="-",v.replace(/[<>v^]/g,(p,i)=>{c=o=>v[i+o]!=q;with(Math)if(p<"?"?c(l,q="|")&c(-l):c(1,q="-")&c(-1))d=(atan2(x=i%l-s%l,y=(i/l|0)-(s/l|0))*180/PI+270)%360,u=sqrt(x*x+y*y)}),u[p="toPrecision"](3)+` units @ ${d[p](3)} degrees`)

Explanation

Input must be padded with spaces. Uses all bonuses.

v=>(
  l=v.search`
`+1,                                                     // l = line length
  s=v.search`x`,                                         // s = index of start point
  u=0,                                                   // u = units
  d=                                                     // d = degrees
  w="-",                                                 // w = cardinal direction
  v.replace(/[<>v^]/g,(p,i)=>{                           // for each endpoint
    c=o=>v[i+o]!=q;                                      // compares cell at offset to char
    with(Math)                                           // save having to write "Math."
      if(p<"?"?c(l,q="|")&c(-l):c(1,q="-")&c(-1))        // check for line branching off
        d=(atan2(
          x=i%l-s%l,                                     // x = relative x
          y=(i/l|0)-(s/l|0)                              // y = relative y
        )*180/PI+270)%360,                               // convert to degrees
        u=sqrt(x*x+y*y),
        w="N S"[sign(y)+1]+"W E"[sign(x)+1]              // get cardinal direction
  }),
  u[p="toPrecision"](3)+` units @ ${d[p](3)} degrees `+w // format output
)

Test

var solution = v=>(l=v.search`
`+1,s=v.search`x`,u=0,d=w="-",v.replace(/[<>v^]/g,(p,i)=>{c=o=>v[i+o]!=q;with(Math)if(p<"?"?c(l,q="|")&c(-l):c(1,q="-")&c(-1))d=(atan2(x=i%l-s%l,y=(i/l|0)-(s/l|0))*180/PI+270)%360,u=sqrt(x*x+y*y),w="N S"[sign(y)+1]+"W E"[sign(x)+1]}),u[p="toPrecision"](3)+` units @ ${d[p](3)} degrees `+w)

<textarea id="input" rows="6" cols="60">x       
|       
|<-----^
|      |
v------></textarea><br />
<button onclick="result.textContent=solution(input.value)">Go</button>
<pre id="result"></pre>