Most people are confused on how archer is suposed to work, well here is how:
First Archer needs to use pre projection, to raise his projection level to a level, second this allows him to chose his other moves to put to use, once you have used pre projection six times and you have unlocked his noble phantasm, it will allow you to use pre projection regardless of the 5x limit, it also increases the overall strengh of the pre projections, making them much much more powerfull (my archer could deal with ease 40.000 damage pts with only his phatasm on and using fake helix sword).
Caster needs the following amount of points to reach an EX on one of her stats
STR 161 MAG 91
DEF 161 LCK 198
AGI 107 Total: 620 points
Keep in mind that this is impossible due to the max points one can get per file is off 297, the only way to do this is via cheating.