Yes, this clearance of the tie rod to teh t-bar needs to be very close to minimize bump steer issues.
Washers are fine for this. I like to use GM type control arm alignment shims because they are slotted, come in varying thicknesses, and have a tab to hold on to them with. Tiltiing the box is not a big deal, but you do want to check its relative position to the idler as well or you can get unequal bump issue from right turn to left turns. This is why you want to check the center link's position to the floor under the shimmed pitman and compare that measurement to the same position at the ilder connection.
Moving the idler is more involved as it will need to be removed and the mount hole slotted to get the ilder aligned, then a washer needs to be welded to the mount to hold the idler in position. Ideally you would want both the pitman and idler measurements to be dead nuts identical and if your planning on autocrossing or road racing the car, should make every effort to make them the same. If you are just doing casual driving to shows, you would probably be okay with a minor difference.