When solving the edges, how can i swap two edges in the "last layer" ? Both F to L, F to R and also F to B. Anyone have any nice alogarithms for this? Also if its relevant, i use the method where you solve the normal skewb first, then place edges.

This is discussed here:

viewtopic.php?f=8&t=20008

Short story: You will have to break up some of what you have done, it is easier to solve edges earlier.
PS A photo would be helpful.

Cheers,
Burgo.

If you look at my post from January 11th in the thread mentioned by Burgo, you'll find a pure 3-cycle for edges. You'll need setup moves!
To me it seems quite natural to solve it as a normal Skewb and handle the "new" pieces later.
If you start with the edges - which is very easy - you'll have to solve the corners later. Some people do not find this step so easy.
EDIT: I assume that you mean by "edges" the pieces with two stickers. A swap of just two is NOT possible. If you have such a situation, somebody has played a bad joke with your Master Skewb.