Yes you can, however the existing pavers must be sound and you might have to use cement to bond the new pavers...... then you might have hight problem, if the extra hight is not a problem you are good to go
YES, VERY EASILY
ABSOLUTELY, SAND BED AND LAY. MORTAR THE OUTSIDE EDGES TO BIND.
The answer is "No" if your house is the Houston clayey soil. You must place 6" of coarse sand under the pavers and you must compact the sand using a compactor machine. If you try do the shorter cut you will see that in less then one year time; you will notice some pavers movement.