I would also be interested in the damage of the Borg tractor beam.
Here is some info on shield regeneration:
"this means that 1 face of your shields ( face being the one of the 4 sides of your shields)... will regenerate a percentage of itself every 1/4 turn... not all shield faces, just 1 face... and it should rotate around your ship in the regeneration... regen Front at 1/4 turn, regen left after another 1/4 turn etc... all 4 faces should go through 1 regen cycle in 1 complete turn..."
If a shield needs no regeneration then its percentage is not given to the other shields that need regeneration. I would assume shield regeneration under cloak is the same as un-cloaked. I have no idea about when shields get turned off.
Regarding the shield inverter, I am pretty sure it is 3 points to each shield. It would be nice to have some verification. Also, when a shield is down, do the points of damage meant for that shield go to hull, even if you had a subsystem targeted?
On your phaser overloading, the remaining phaser can only be overloaded by 100% (+50% damage). Your extra power goes to waste if you have no place to place it.