Answer #1.
Your post is not outputting the "Z" clearance move 1st.
This will take some post modifications.
Pretty easy stuff there.
Easier fix is to MOVE the cutter up after you set tool length offset.
This is pretty much standard practice and easier than modifying the post.
Answer #2.
When selecting contours it is VERY important to select the PROPER direction.
For climb cutting, select the contour so it chains CLOCKWISE for the outside, and COUNTER-CLOCKWISE for the inside.
Reverse these rules for conventional cutting.
Yes you can change which side of the contour the cutter follows but unless you are consistant with which direction you pick them it can be confusing.
Pocketing will ALWAYS use the INSIDE of the most OUTSIDE contour.
This allows for pocketing with "islands".
Answer #3.
Most drawing programs like Illustrator, don't usually draw arcs as arcs.
They draw them as a series of closely spaced lines.
There is no actual "center".
The solution for this is to create an 3 point circle in Mcam using 3 of the line endpoints.
A better solution is to use Mcam's own CAD interface to create your part.
Good Luck,
ObrienDave. MasterCam since V6. Gcode since 1983.
The nose you punch today may belong to the butt you have to kiss tomorrow.